Westlab LAB ANSWER Magazine 2017

LAB ANSWERS Magazine : Edition 1

I

November 2016

KEY ARTICLES IN THIS EDITION The 4 New Elements on the Periodic Table The GHS: What You Need To Know What is the Difference Between Turbidity and TSS? Nitrile Vs Latex Vs Vinyl Gloves How Do I Choose the Right Microscope?

CONTENTS 02

The 4 New Elements of the Periodic Table

23

Distilled Vs Deionised Water: What is the Difference?

04

The GHS What You Need to Know

25

Choosing a Microscope (Educational)

06

6 Key Considerations When Purchasing Laboratory Equipment

27

What is the Difference Between Conductivity (EC) and TDS?

08

How Long Does a Deionised (DI) Cartridge Last?

29

7 Reasons Why you Should Wear a Lab Coat Laboratory

09

The Difference Between Distilled and Demineralised Water

31

Purchasing Ethanol in Australia Tips to Properly Care for your Microscope

10

33

Difference Between RCF and RPM in Centrifugation

35

Dangerous Goods Storage in theLaboratory

12

10 Tips to Improve your Pipetting Technique

37

The STEM Global Movement

14

Nitrile Vs Latex Vx Vinyl Gloves

39

The Difference Between a Lab Oven and a Drying Oven

16

What is GHS and When Will it be in Use?

41

What you Need to Know Before Purchasing a Ducted Fume Hood

17

Why Doesn't a pH Sensor Display pH7 in Deionised or Distilled Water?

43

A Guide to Choosing a Pipette Tip

18

10 Tips to Run a More Efficient Laboratory

45

Measuring Melting Point Measurement of pH in Plant Tissue

20

The 4 New Elements of the Periodic Table

47 48

3 Things to Consider When Choosing a Centrifuge Tube

21

Why Use a Non-Bleeding pH Test Strip?

49

What is the Clean-in-Place (CIP) Method?

22

What is the Correct Way to Store a pH Electrocode?

51

Sparkling Glassware without the Side Effects

CONTENTS 2016 EDITION

1

THE 4 NEW ELEMENTS ON THE

PERIODIC TABLE

I

n June of 2016, it was publically announced that the periodic table will soon have four new elements added to it. The International Union of Pure and Applied Chemistry (IUPAC) has worked with those laboratories that discovered the elements to name them and has now released the new periodic table for a five-month public review period which expires on the 8th of November, 2016.

After the review period, the IUPAC Council will formally approve the revised periodic table.

The new elements will be added to the lower righthand corner and consist of: • Nihonium

(symbol Nh) - atomic number 113

• Moscovium (symbol MC) - atomic number 115 • Tennessine (symbol TS) - atomic number 117 • Oganesson (symbol Og) - atomic number 118

2 www.westlab.com.au

In January, the new elements were first announced and given interim names until formal names were released. The rights to name the elements were given to those research teams that discovered them.

The US , Russia, and Japan were credited with the discovery of the new elements and the names were announced in June. Whilst these teams have the rights to name the elements, they do have to follow a naming convention as outlined by the IUPAC which states that any new element must be named after either: a. a mythological concept or character (including an astronomical object), b. a mineral or similar substance, c. a place, or geographical region, d. a property of the element or e. a scientist.

How Exactly Were These Elements Found?

The Meaning Behind the Names • Nihonium - Nihon is one way to say “Japan” in Japanese. As this was the first element discovered by an Asian country, Japan wanted the name to represent the geographical region. Nihonmeans “the Land of Rising Sun” and provides a direct connection to Japan as a nation.

• Moscovium - Moscovium also represents a geographical region, specifically, the Moscow region which is where the discovery experiments were conducted.

• Tennessine - Tenessine recognises the laboratories that contribute to element research in Tennessee in Knoxville.

• Oganesson - Oganesson attributed its name to a scientist following the IUPAC naming convention.

Professor Yuri Oganessian (born 1933) is a Russian nuclear physicist who is credited with three confirmed element discoveries.

Firstly, of the 118 known elements, 94 were found naturally on Earth. This leaves the remaining 24 elements that are not found naturally, meaning they were created in a lab. Creating ‘man-made’ elements involves using particle accelerators to smash atoms together in the hope that they may fuse to become a new element. If the proton count is one that has never been reached before, a new element is formed. To become a new element, however, the experiment must be recreated or reproduced by other scientists to ensure they get the same result. Post November and provided all goes well with the publlic review period, the periodic table will be officially updated to include the four new elements. Westlab are getting in early and releasing updated wall hanging periodic tables within the next coupe of months. If, for whatever reason, the updated periodic table is rejected during the public review period, Westlab will refund in full the purchase price of the periodic table!

THE GHS:

WHAT YOU NEED TO KNOW

WHAT TO LOOK FOR WHEN PURCHASING A DANGEROUS GOODS CABINET?

More information on the GHS can be obtained from SafeWork Australiahttp://www.safeworkaustralia.gov.au/.

T

he GHS is an acronym for the Globally Harmonised System of Classification and Labelling of Chemicals and is a new naming and labelling system that is in the process of being implemented globally. It was developed by the United Nations and the transition to the new GHS system began in Australia in January of 2012 and will be fully implemented by January 1, 2017.

January is now fast approaching and you would have noticed many manufacturers and importers are well underway into their transition to the GHS.

What is the GHS? and When will it be in Use? The GHS was developed as a global unified system to classify chemicals and was designed to replace the different labelling and classification systems used throughout the world to create one single harmonised system. The GHS is systematically being introduced in many countries globally.

Australia is a progressively implementing the GHS system and many manufacturers and importers have begun the changeover to GHS which you may notice on chemicals you currently purchase. The GHS, however will not become mandatory until the 1st of January 2017.

4 www.westlab.com.au

The GHS in Regards to Chemical Storage Australian Standards 1940 (The storage and handling of flammable and combustible liquids) states that storage cabinets require a Class 3 dangerous goods label with sides of at least 250mm nominal length. There is currently no plans for the GHS labels to be required on storage cabinets and the changeover to GHS labels only affects packaged dangerous goods & hazardous substances.

Westlab introduced the Modulab 4-IN-1 Dangerous Goods Cabinets in July 2015 with an initial plan to switch these cabinets to the new GHS labelling system. As the GHS changeover makes no reference to labels on storage cabinets. Modu lab Systems have returned to the existing labellling system for their Dangerous Goods Cabi nets until such a time when storage cabinets are acknowledged in the GHS changeover. Modulab Systems will continue to monitor the progress of the GHS system in Australia and provide further updates when they become available.

For more information on the GHS, please visit Safework Australia http://www.safeworkaustralia.gov.au/

What to Look For When Purchasing a Dangerous Goods Cabinet?

There are a lot of dangerous goods storage cabinets (DG cabinets) available in the market and it can be often be quiet overwhelming when determining what type of cabinet you should purchase for your laboratory. There are a range of considerations to take into account prior to purchasing. To assist you with your decision making process, we’ve complied a list of items that should be considered and will help to streamline your decision.

• Compliance - First and foremost, you need to look for a cabinet that is fully compliant with Australian Standards, in particular AS1940-2004 which refers to the storage and handling of flam mable and combustible liquids. Most suppliers should state quiet clearly whether the cabinet is compliant or not. If they don’t then it may be worth a quick phone call to find out. Compliance is extremely important, not only does it prevent potential injuries to workers, it also eliminates financial liability due to compliance.

• Self-Closing Door/s - If the cabinet is compli ant as mentioned above, then it will have self closing doors. Nevertheless, it is still worth men tioning for educational purposes. AS 1940-2004 states that all cabinet doors shall be self-closing, closefitting and held shut automatically by catches at two or more points. What this means is that the doors should close by themselves and latch shut automatically. However, if storing class 5.2 dangerous goods, doors are still required to close automatically by they cannot latch or close. This is due to class 5.2 chemicals reading an allowance for pressure to be released caused by accelerated decomposition.

• Non-Metal Cabinets - If you have decided to purchase a non-metal (polyethylene) cabinet, it is important to ensure that the cabinet is 100% non metal in construction. We have seen many of times cabinets with metal components that corrode over time defeating the purpose of having a non-metal cabinet in the first place. Make sure it is 100% non-metal, this includes hinges, locks, screws etc.

cabinets but are sometimes required as a risk control measure when the cabinet is located in enclosed areas where extremely toxic or corro sive substances are being held. It is usually the end users responsibility to install the ventilation ducting but in order to do this, the cabinet must have pre-fitted venting bungs. Some suppliers will charge extra to provide a cabinet with venting bungs whilst others include as standard. It is worth confirming if ventilation is something that may be required either now or anytime in the future and ensure the cabinet you purchase acco modates this. Westlab’s 4-IN-1 cabinets, for example , come standard with venting bungs allowing for venting immediately or in future if required.

• Visual Component - Contrary to popular belief, there is no standard colours that a cabinet must adhere to. You will often see yellow for flammable, blue for corrosive etc. but you aren’t actually required to have specific colours for different types of dangerous goods. This gives you the flexibility to choose a cabinet that is more visually appealing and blends in well with your laboratory.

• Delivery Charges - Cabinets are often expen sive to ship, especially if you are in a remote area of Australia. To save on unexpected shipping charges, it is worth asking your potentical supplier to include any delivery charges when you are obtaining a quote. This allows you to get a full cost upfront and helps when compairing suppliers. You may be gettng a cabinet at an economical price.

Hopefully these considerations will drastically reduce the decision making process.

Choosing the right cabinet will ensure it stands the test of time and save money in the long run.

• Venting - Venting is not normally required on DG

THE GHS: WHAT YOU NEED TO KNOW 2016 EDITION

5

6 KEY CONSIDERATIONS WHEN PURCHASING LABORATORY EQUIPMENT Remember, a good supplier will have your best interests in mind and won’t try to sell you something you don’t need. Look for suppliers who you can trust and are authentic in their approach, it will make your life a lot easier both now, and anytime you need their assistance in the future.

P

urchasing laboratory equipment is one of the biggest investments your laboratory will ever make. It is essential that you consider multiple facets of the purchase to maximise your return on investment. We’ve compiled a list of key things to take into consideration when choosing the best laboratory equipment to suit your needs.

1. Availability - Generally, when you are looking at buying laboratory equipment, you will want the equipment to be delivered promptly. Often laboratory equipment will be imported from overseas and out of stock items could take up to 10 weeks to deliver. Look for products that are in stock and available for immediate delivery.

If stock isn’t available, make sure you get your potential supplier to quote a lead time allowing you to compare price with the corresponding lead time to determine if you can compromise on lead time for a better price or vise versa.

2. After Sales Support - It is often a good idea to ask your supplier what kind of after sales support they offer. If something was to go wrong or you need assistance with using the equipment, it is great to know that you can pick up the phone and get prompt support with your enquiry.

3. Warranty - Warranty is super important when considering a piece laboratory equipment.

Warranties do vary dramatically between manufacturers and the type of warranty support you receive can also vary. Here are some

6

www.westlab.com.au

questions to ask when looking into a warranty: o How long is the warranty period? - Take a

look at the warranty period being offered.

Check to see when the warranty begins (does it begin at time of purchase? Or time of receipt?) and when it expires. Do you need to register the product to obtain the warranty? o What voids the warranty? - It’s worth taking the time to look into what will void the warranty and whether your application may risk doing this. Warranties are generally only covered provided you use the product as directed. There is nothing worse than sending the equipment back for a warranty claim only to have the manufacturer advise that the warranty is void. o Who do I contact to make a warranty claim? - Who do you contact for a warranty claim? Do you contact the seller or manufacturer? Ideally you want to claim a warranty from the company in which you purchased the equipment as they have a record of everything in their system and can deal with your warranty promptly. o What is the warranty process? - What is the process of a warranty claim? Are you required to send the product back to your supplier and will you have to pay for this return freight charge? Will the supplier repair the product, replace it, or refund the

an approved servicing technician at set intervals.

5. Usage - Usage is an often overlooked factor but should be considered in the decision process.

Equipment that is regularly used on a daily basis will mean quality and reliability is much more important than someone who uses the equipment a few times per annum. Take into account your usage and purchase accordingly.

The higher the usage, the more performance and reliability will become of further importance.

transaction. Are there any additional costs that you may need to cover in the event of a warranty claim. It is worth looking into this process upfront. A hassle free warranty claim procedure is a huge advantage and worth taking into consideration. o Is there an extended warranty option? Extended warranties are sometimes offered by suppliers for an additional charge. When deciding on whether an extended warranty is worth it or not, take into account the cost of the equipment and the corresponding extended warranty charge to determine if the additional investment is worth it. It’s also worth looking at what the extended warranty covers and if it is different to the standard warranty. Don’t be pressured into an extended warranty, do some quick calculations on your own accord to help you make an informed decision.

4. Servicing - Will your equipment require routine servicing? If so, will this be done by internal maintenance personnel or do you require a more specialised technician? Some manufacturers have approved servicing technicians located throughout Australia. Your supplier should be able to help you source these technicians to arrange servicing of your equipment. Make sure you look into the servicing requirements in regards to warranty, in some instances, warranty is void if the equipment hasn’t been serviced by

6. Price - While many would argue that price should be at the top of the list in the decision making process, there are a few things to consider when looking at the price. Remember, the cost price of the equipment is not the total cost of ownership (TCO). There are many things that add to the TCO over the lifetime of the product, these can include installation costs, operating costs, maintenance costs, and even things such as user-efficiency. TCO can be compared with total benefits of ownership (TBO) which looks into what return the company will see from purchasing the equipment. Depending on what equipment is being purchased, an analysis of TCO and TBO may or may not be required. For example, it is probably not worth doing this analysis when purchasing 1 piece of equipment valued at $200, but may be hugely valuable to do so on a piece of equipment worth $20,000. It is a good idea to put a procedure in place whereby a TCO/TBO analysis is required for equipment purchases over X amount.

It can certainly become a daunting task when trying to decide on the right laboratory equipment. Hopefully these 6 considerations will help you streamline your decision making process and substantially reduce the buying cycle. Your supplier should be there to guide you through the process and support you in your decision. Remember, a good supplier will have your best interests in mind and won’t try to sell you something you don’t need. Look for suppliers who you can trust and are authentic in their approach, it will make your life a lot easier both now, and anytime you need their assistance in the future.

6 KEY CONSIDERATIONS WHEN PURCHASING LABORATORY EQUIPMENT 2016 EDITION

7

HOW LONG DOES A DEIONISER (DI) CARTRIDGE LAST? Deionisation (DI) is a common form of purifying water. Mixed Bed Resin Filters are the most popular and far exceed the performance of older type of cartridges.

D

eionisation (DI) is a common form of purifying water. Mixed Bed Resin Filters are the most popular and far exceed the performance of older type of cartridges. The DI resin process purifies the water by passing water through two resins that have opposite charges to remove ionised minerals and salts from the water.

Simply put, DI resins attract non-water ions and replace them with water ions which will result in more pure water.

The mixed bed resin filters include cartridges and need to be replaced when the resins lose their ability to properly purify the water. The best DI resin to use is colour changing resin that will change from a blue/green colour to a brown colour when the resin is no longer capable of properly purifying the water. This indicates that the cartridge needs to be replaced and is a good visual indicator.

The DI Cartridge Lifespan DI removes total dissolved solids (TDS) from the water as the water passes through these DI resins. Depending on the TDS of the incoming water, the life of the cartridge will vary dramatically. You will get much greater purified water output from soft water than you would hard water.

If you are experiencing less than desired litreage output from your DI cartridge, it is worth firstly checking the TDS levels of the source water. TDS levels

8

www.westlab.com.au

of standard tap water will vary greatly depending on your location. For example, Melbourne (or parts of Melbourne) have a TDS level of around 40 mg/L whilst a more rural area may have a TDS level in excess of 100 mg/L. Australian Drinking Water Guidelines (ADWG) state that tap water shall not exceed 600 mg/L so it is safe to assume that tap water across Australia will vary between 0 to 600 mg/L. As such, your location will significantly impact the life of your DI cartridge.

Another factor that will reduce your litreage output is the levels of CO2 present in the source water. CO2 can decrease the life of the cartridge dramatically and can often be the cause of DI resin depleting relatively quickly. If your TDS levels of the source water are at an acceptable level and you are still finding the cartridge not lasting long, high CO2 levels in the water is more than likely the problem.

Increase the Lifespan of a DI Cartridge Whilst in most instances, you should be able to simply connect a water deioniser to your mains water and get a good lifespan from your cartridge. If you are finding as mentioned above that your TDS or CO2 levels are quite high and dramatically affecting your cartridge life then it may be worth considering adding in an additional step to the purification process. Adding in a reverse osmosis (RO) system prior to the water passing through the DI resins will help to reduce the TDS levels of the water and also gives the water some time to gas off the excess CO2 if set up correctly. For most laboratories, however, this step is not required and only needs to be considered if you require ultra pure water or if your cartridges are depleting too quickly.

THE DIFFERENCE BETWEEN DISTILLED AND DEMINERALISED WATER

D

istillation and demineralisation are both forms of purifying water but they have different methods of achieving this purification. The two methods do produce different results and it is worth looking into both so that you are equipped with the knowledge of the differences between them.

Distilled Water Distilled water simply refers to water that has undergone a process where the water is heated to above boiling point and the steam from that water is captured and cooled to produce liquid distilled water. This type of the purification process is the most common method and the end result is a very pure product. This method removes bacteria, organic and inorganic particles, viruses, minerals, etc. from the water and once the water has gone through this process, must be stored in a sterilised container so to maintain its purity. The distillation process also removes salts, metals, and minerals.

There can be volatile organic compounds and gases that make their way through the distillation process due to these compounds having a lower boiling point to water. Usually, manufacturers will add in extra filtering processes to absorb any remaining compounds and gases.

Demineralised Water Demineralised water is a more economical means of water purification and simply refers to any water that has undergone a process to remove minerals

and salts from the water. This type of water is used in applications where water with low salt content or low conductivity is required. Demineralised water is made by passing the water through specially manufactured resins. The resin is designed to exchange ions in the water so that the final result leaves you with the chemical composition of pure water.

While demineralised water is virtually free from minerals and related substances, there can be very tiny amounts of dissolved minerals that will always remain. However, the advancements in technology for demineralisation ensure the end result is very high quality water.

What is the Difference Between Distilled and Demineralised Water?

Distilled and demineralised water are produced through different methods of purification and as such, produce a different end result. Demineralised water has had minerals removed so that you are left with H2O. The problem with demineralisation is that it will not remove bacteria or viruses like distilling would. Distillation is a very effective method and will remove 99.9% of contaminants.

Simply put, where distillation is effective at removing suspe nded particles, organic materials, bacteria, viruses, and physical impurities, demineralisation is not. Distillation is a much more effective method of purifying the water.

Many manufacturers these days will actually put the water through both purification methods to ensure you get as pure water as possible. The reason for this is that the demineralisation process removes trace elements that manage to make their way through the distillation process.

THE DIFFERENCE BETWEEN DISTILLED AND DEMINERALISED WATER 2016 EDITION

9

DIFFERENCE BETWEEN

RCF AND RPM IN CENTRIFUGATION

W

hen dealing with centrifuges, you will come across two different units of measure: The Relative Centrifugal Force (RCF) and Revolutions Per Minute (RPM). It is important that you are aware that the two are very different, get them wrong (which isn’t as uncommon as you might think) and the experiment will be ruined. Let’s take a look at both RCF and RPM in more detail and determine if there is any correlation between the two.

Revolutions Per Minute (RPM) Revolutions Per Minute (RPM) in regards to centrifugation is simply a measurement of how fast the centrifuge rotor does a full rotation in one minute.

Basically, it is telling us how fast the rotor is spinning. Centrifuges will have a speed range that they are capable of achieving and will vary depending on the centrifuge. A low speed centrifuge might spin at as low as 300 RPM, whilst a high speed centrifuge could spin up to 15000 RPM. Ultracentrifuges are also available and are the most powerful type of centrifuge, they can spin in excess of 150,000 RPM.

Revolutions Per Minute (RPM) Relative Centrifugal Force (RCF) or g-force (both

10

www.westlab.com.au

are the same, RCF is expressed as units of gravity) is a measurement of the gravitational force that a sample is subject to. The force is generated from the spinning of the rotor which, in turn, exerts this force outward on the centrifuge tube. Not only does RCF take into account the speed of rotation, it also measures the distance from the centre of rotation to give us a g-force measurement. RCF is the preferred method of measurement as it will remain the same even if you are using a different centrifuge with a different rotor size.

What’s the difference between RPM and RCF? Both RPM and RCF/g-force can be measured in centrifugation but as we have just explored, the two are very different. RPM simply measures how fast the rotor is spinning and while this information is helpful, it is lacking the ability to truly measure the g’s the sample is subject to. A centrifuge spinning at 5000 RPM, for example, will spin at 5000 RPM regardless of the centrifuge being used or the size of the rotor. RCF accommodates the rotor size into its measurement so we can determine the gravitational force being applied. This is why you should always document your procedures as g’s rather than RPM.

the maximum, minimum, and average which are You may notice that your centrifuge only has a the distances to the top, bottom, and middle on setting for RPM. If this is the case, you can use a formula to convert RPM to RCF which is outlined the centrifuge tube from the centre of the rotor.

It is absolutely vital that you below. If you are currently are aware of the difference in the market for a centri“THE EASIEST WAY TO ENSURE YOU ARE between RCF and RPM as it fuge, try to find one that can be disastrous if you get measures both RPM and ACCURATELY RECORDING RCF IS TO USE RCF to save you having to them wrong. You should always report your results in manually convert them.

A CENTRIFUGE WHERE YOU ARE ABLE Most modern centrifuges RCF as this remains conTO SET THE RCF FOR THE EXPERIMENT.” stant irrelevant of the cenwill have this functionality where you can simply trifuge you are using. Two switch between the two interchangeably. The fordifferent centrifuges running at the same RPM can have a completely different RCF reading. The mula below allows you to convert RPM to RCF but the issue with using this formula is that you have easiest way to ensure you are accurately recording RCF is to use a centrifuge where you are able to determine the radius. Generally, the manufacturer of the rotor will provide three radius values: to set the RCF for the experiment.

RCF

= 11.18 x r x

(

RPM 1,000

)

2

* r = radius in cm

DIFFERENCE BETWEEN RCF AND RPM IN CENTRIFUGATION 2016 EDITION

11

10 TIPS TO IMPROVE YOUR PIPETTING TECHNIQUE

It

is important to establish a proper pipetting technique as poor techniques can dramatically reduce the accuracy and performance of the pipettor. It is worth taking the time to fine tune your technique to ensure you are working as efficiently and effectively as possible. We have compiled a list of the top 10 pipetting technique tips to assist you in achieving a great technique.

1. Correct tips - The first tip, and probably the most obvious, is to ensure you are using the correct pipette tip. Most manufacturers of pipette tips will offer a compatibility chart such as the ISG® compatibility chart on our website. Incompatible pipette tips can reduce accuracy and precision so it is important that you choose a high quality pipette tip suited to your pipette. Low retention tips are recommended for high accuracy.

2. Pre-wetting - It is important that you pre-wet the pipette tip for a couple of reasons. Firstly, it allows you to flush out residual substances and prevent cross-contamination. Secondly, it increases the humidity resulting in less evaporation (evaporation can cause significant sample loss). To pre-wet the tip, simply draw and expel liquid fully at least three times before use.

3. Pipetting angle - It is important to ensure you aspirate and dispense at the correct angles to ensure accuracy. Ensure you are aspirating at 90° and that you pull the pipette tip out of the

12

www.westlab.com.au

center of the container at 90° also. When dispensing, ensure you hold the pipette at an angle (10-45°). Working to these angles ensures the desired liquid amount is drawn into the tip properly and that all of the liquid is fully dispensed without leaving any residue in the tip.

4. Dispensing - When dispensing the sample, it is important that you dispense pressing the tip to the side of the container or into the liquid already in the container. Make sure it is also at an angle as mentioned above.

You should not dispense into direct air as this can affect your measurement results.

5. Standard mode pipetting - Ensure you are using standard mode pipetting rather than reverse pipetting for the most accuracy and precision. Reverse pipetting can be used when you are working with viscous samples. If you use this reverse mode with normal fluids, the pipette will tend to deliver more than the desired volume. But if you were to use standard mode with viscous samples, however, you would receive less than the desired volume.

6. Temperature - Believe it or not, temperature is probably the most important factor that can influence a pipettes performance. The specifications provided for your pipette are often based on testing at room temperature (~20-25°C). If pipetting is performed at temperatures outside of this range, it can affect the amount of liquid dispensed.

more relaxed grip. Look for a comfortable and well balanced finger hook which will reduce hand stress.

7. Ergonomics - A problem that can arise with individuals who use pipettes on a regular basis is Repetitive Strain Injury (RSI) which occurs when the same physical exercise is performed in excess amounts. RSI from pipettes can cause some serious harm to users where they can experience muscle and joint pain. The most effective way to prevent RSI is to use an ergonomic pipette and focus on proper technique. The design of the pipette can have a significant impact on the comfort and safety for the user. Spend some time looking into the design of the potential pipette you are considering for purchase. A good pipette design will allow for neutral positioning of the hand and wrist. Here are some design aspects to consider: o Comfort - A good contoured body shape

ensures a perfect fit for all hand sizes.

o Versatility -

Is the pipette suitable for both left and right-handed users?

o Plunger - Look for a plunger that is thumb-

friendly with reduced plunger pressure. Also look for comfortable thumb access where you don’t need to over-stretch the thumb.

o Tip Ejection - A good tip ejection sys-

tem can reduce thumb workload by up to 70% easing the pressure on the thumb.

o Finger Hook - A good finger hook will be

able to take the weight of the pipette for a

8. Immersion - It is also important that you place the pipette tip into the sample at the proper immersion depth. Depending on the size/volume of the pipette, the immersion depth will change slightly. Incorrect immersion depth can result in incorrect sample volumes. Remember, keep the pipette as vertical as possible during this process.

Volume I Size 2µL - 10µ 20µL - 100µL 200µL - 1000µL 1000µL - 10,000µL

Immersion Depth 1-2mm 2-3mm 2-4mm 3-6mm

9. Plunging - When releasing the plunger during the aspiration process, do so at a controlled and consistent motion to increase both accuracy and precision. The pressure required will change based on the liquid being aspirated.

10. Pausing - A simple tip that helps to minimise errors is to pause consistently after aspiration for about one or two seconds while the liquid is still in the pipette tip. This allows for the liquid in the tip to “bounce” when the plunger stops which simply gives the liquid time to stabilise.

Having a good pipetting technique will not only assist you with easing strain caused from repetitive use, it will also ensure you drastically improve your accuracy and precision. Good technique also helps you keep your pipettes in excellent condition. It is a good idea for your laboratory to develop standard operating procedures that all staff should follow. You should make sure all staff are trained to work to this standard.

10 TIPS TO IMPROVE YOUR PIPETTING TECHNIQUES 2016 EDITION

13

NITRILE VS LATEX

VS VINYL GLOVES When deciding what glove is most suitable. Ask yourself; how much protection do I need? And do I need to consider potential allergies?

T

he three most popular glove materials on the market today are nitrile, latex, and vinyl. We have seen the popularisation of the nitrile glove in recent years but what’s the difference? And what type should you be using? In this article, we will explore the these glove types so you can make an informed decision of what type is most suitable for your laboratory.

Nitrile Gloves Nitrile is a durable, synthetic rubber technically known as acrylonitrile-butadiene rubber and was developed for a number of reasons, namely, due to the issues surrounding common allergies to latex gloves and the lack of protection against solvents that latex offers. The gloves were first introduced in the mid 1990s and were aimed at medical applications but have since become widely popular for laboratory and industrial customers.

This is one of the main advantages of a nitrile glove and is often used when the user will come into contact with hazardous substances. For a full comparison of chemical resistance between glove materials, see our chemical resistant chart (note: actual chemical resistance can vary between manufacturers).

A big advantage of nitrile gloves (often overlooked) is that the material has a tendency to tear when punctured. This is an easy way to recognise that the glove has been compromised. In comparison, a latex glove will remain intact and a small puncture could potentially be overlooked. This is a major advantage of a nitrile glove over a latex glove when dealing with hazardous substances. Please note that it is always important to check your glove for any punctures prior to using it with any hazardous substances. While the Nitrile tear feature is an advantage, it cannot be relied upon as an effective preventative measure.

Latex Gloves

Nitrile gloves are latex free and have very low allergy rates (less than 1% of users).They are the most popular type of glove used today which is mainly attributed to their versatility (can be used in almost every industry), very low allergy rates, and price. Traditionally, nitrile gloves were much more expensive than latex but with their ever increasing popularity, we have seen prices drop in recent years to the point where they are on par, if not lower priced than latex gloves.

Latex gloves are the more traditional glove, they are made out of rubber and have been used for many years. While there are allergy concerns with latex gloves, they are sometimes more favourable to users over a nitrile glove mainly due to comfort and strength. Generally Latex gloves will be more comfortable, sensitive, and provide better grip, although the modern advances in nitrile glove manufacturing has seen nitrile gloves become more comfortable, thinner, with better dexterity.

Nitrile has excellent chemical resistant when compared to latex.

A concern with latex gloves and the reason why they have been

14

www.westlab.com.au

banned in some medical and educational institutions is the common allergic response people have to the latex material. Whilst allergies to latex are often not life threatening (but can be), it does cause discomfort to the individual. We generally see a skin reaction occur anywhere from immediate exposure up to hours after exposure. In rare instances, a more severe reaction may occur like a life threatening anaphylactic attack. Allergic reactions can increase in severity with repeated exposure which is also a cause for concern. It is worth considering that even if you don’t have an allergy to latex, someone that you may come into contact with while wearing the gloves may.

Latex gloves provide exceptional physical barrier performance similar to nitrile but they do not offer any real protection against solvents which is another downfall of the latex material. If chemicals resistance is important, nitrile would be a better choice.

Vinyl Gloves Vinyl gloves are also a popular glove but are only used in certain environments. Vinyl gloves are latex-free and are often the cheapest option of the three materials. This type of glove is generally used in a high volume environment when dealing with non-hazardous materials as they offer very minor protection.Vinyl gloves are generally loose fitting and less elastic than

W

a nitrile or latex glove resulting in a glove that does not fit very well and is uncomfortable to wear. As such, you will generally find users are only wearing them for a short period of time (5 minutes or less).

Vinyl gloves have a low resistance to many chemicals and should not be used in any environment where hazardous substances are being handled. Generally, we find vinyl gloves are used in the food and beverage industry and are good for low-risk tasks where the gloves are only used for a short period of time.

Allergic reactions to vinyl gloves are pretty much nonexistent and reports of allergic reactions are rare. While people do complain of an allergic response from wearing vinyl gloves, the problem is actually a skin irritation from lack of ventilation whilst wearing the gloves. The hand will perspire and irritate the skin as the glove traps the heat and perspiration inside the glove.

In recent years, nitrile has become by far the most popular choice of gloves across most industries. Their synthetic material eliminates the common allergy factors found in the latex material and superior chemical resistance is a big advantage to the nitrile material. So when deciding what glove is most suitable.

Ask yourself; how much protection do I need? And do I need to consider potential allergies?

hile people do complain of an allergic response from wearing vinyl gloves the problem is actually a skin irritation whilst wearing the gloves.

NITRILE VS LATEX VS VINYL GLOVES 2016 EDITION

15

WHAT IS GHS AND WHEN WILL IT BE IN USE? More information on the GHS can be obtained from SafeWork Australiahttp://www.safeworkaustralia.gov.au/.

T

he GHS is an acronym for the Globally Harmonised System of Classification and Labelling of Chemicals and is a new naming and labelling system that is in the process of being implemented globally. It was developed by the United Nations and the transition to the new GHS system began in Australia in January of 2012 and will be fully implemented by January 1, 2017.Â

What is the GHS and when will it be in use?

The GHS was developed as a global unified system to classify chemicals and was designed to replace the different labelling and classification systems used throughout the world to create one single harmonised system. The GHS is systematically being introduced in many countries globally.

Australia is progressively implementing the GHS system and many manufacturers and importers have begun the changeover to GHS which you may notice on chemicals you currently purchase. The GHS, however, will not become mandatory until the 1st of January, 2017.

The GHS In Regards To Chemical Storage Australian Standards 1940 (The storage and handling of flammable and combustible liquids) states that storage cabinets require a Class 3 dangerous goods label with sides of at least 250mm nominal length. There is currently no plans for the GHS labels to be required on storage cabinets and the changeover to GHS labels only affects packaged dangerous goods & hazardous substances.

Westlab introduced the Modulab 4-IN-1 Dangerous Goods Cabinets in July 2015 with an initial plan to switch these cabinets to the new GHS labelling system. As the GHS changeover makes no reference to labels on storage cabinets, Modulab Systems have returned to the existing labelling system for their Dangerous Goods Cabinets until such a time when storage cabinets are acknowledged in the GHS changeover. Modulab Systems will continue to monitor the progress of the GHS system in Australia and provide further updates when they become available.

More information on the GHS can be obtained from SafeWork:

safe work australia http://www.safeworkaustralia.gov.au/

16

www.westlab.com.au

WHY DOESN'T A PH SENSOR DISPLAY PH7 IN DEIONISED OR DISTILLED WATER?

H

ave you ever wondered why you can’t get a consistent pH reading on your distilled or deionised water? Here is why‌

The electrodes of a pH meter will not give accurate values in pure water because distilled and deionised water do not have enough ions for the electrode to function accurately. The readings will most likely fluctuate and be meaningless. For calibration purposes, pH buffer solution is the best way to test your pH electrodes because it has a defined and accurate pH. General tap water normally has enough ions present to allow a pH electrode to function correctly. Because of this, tap water is a good short term 24hr solution for storage.

You must also keep in mind that water (Deionised Water, or Distilled Water) do not have a pH of 7. As soon as water comes in contact with air, CO2 gas starts to dissolve it, forming carbonic acid (H2CO3).

This results in the pH being lower than seven.

To measure the pH of water accurately you will require pH Ionic Strength Adjusters. These adjust the ionic strength of the water without changing the pH of the water making it possible to determine the accurate pH. The purpose of a deioniser and distillation unit is to purify the water by substantially reducing the conductivity. This means you should really be measuring the conductivity, not the pH.

WHY A PH SENSOR DISPLAY PH7 TABLE IN DEIONISED OR DISTILLED WATER? 2016 EDITION THE 4DOESN'T NEW ELEMENTS ON THE PERIODIC 2016 EDITION

17 19

10 TIPS TO RUN A MORE EFFICIENT LABORATORY

F

rom creating a culture of innovation to maintaining your equipment, this article sets out 10 simple tips on how to make your facility more efficient today and more importantly, well into the future!

There are three variables that determine the efficiency of any laboratory: The people, the processes, and the equipment.

The People Right people in the right seats - Your people are the most valuable asset in your laboratory.

Ensure you have the right people in the right seat. Laboratory teams normally require strong leadership, be a strong leader that provides continuous education and training. Set clear achievable objectives for your laboratory staff.

• Create a culture of innovation and continuous improvement - Great ideas come forward in blue-sky* sessions, encourage input from all staff. It is often a good idea to review spaghetti diagrams of individuals to detect and eliminate potential inefficiencies (e.g. moving the centrifuge to a more central location or closer to the regular user/s). It is also helpful to encourage staff to challenge methods (i.e. is there a better way we can do this?) but is important to struc•

18

www.westlab.com.au

ture this process to ensure it doesn’t cause downtime in the laboratory.

The Processes Review the bench space - Being lean does not involve anything too complex. Sketch your process on paper and review the spaghetti diagram.

Ensure your equipment layout is in series to minimise overlap and inefficiencies. Consider the purchase of more equipment to fill the gaps, look at cost of equipment versus return on investment through the saving of downtime.

• Share responsibilities - Make individuals responsible for their space. You should photograph the expected standard and ensure staff adhere to this standard. Making this visual allows staff to understand what is expected of them. Cross training of laboratory staff is vital for an efficient laboratory. If key staff are away, ensure there are others with the skill set and experience to step in and fill the void.

• Start with the end in mind - Knowing what you want to achieve will help you plan and reach your objective in the shortest possible time without doing it at the expense of accuracy and quality. A job well planned is a job half done.

•

•

Manage inventory levels and make visible Manage your inventory so you don’t run out of basics in times of demand. Automated systems or even simple KanBan* systems can be set up with little effort to help manage stock levels. Ensure all laboratory staff are aware of the triggers and the go-to person/s for purchasing. Have a dedicated store area with labeled inventory space to ensure no downtime in finding the right consumables.

The Equipment •

Plan your equipment requirements in advance - Make an equipment calendar if necessary, having an equipment calendar makes it much easier to ensure that everyone has what they need, when they need it. There are plenty of free shared online calendars that can be accessed by everyone in real time.

•

Watch the market for new products that can increase throughput - There are plenty of new laboratory products available every year that seek to increase sample throughput and make protocols more efficient. Look at the most suitable exhibitions for your laboratory type. Many new ideas and concepts are available at exhibitions that will help you maintain a competitive edge.

Look at the long-term investment of equipment when purchasing - Don’t make price the pivot point of every purchase, quality and brand are an essential contributor to a long term quality investment. Find out who has purchased the same equipment and contact them directly to obtain a first hand testimonial. Cross pollinate with similar laboratories that are doing well and see what they are using. Request demonstrations to ensure professional staff are comfortable with items prior to purchase. Look at warranties and service back up from companies offering the products.

• Maintain your equipment - Generally you will get much more life out of equipment that has been maintained. Have a maintenance schedule to ensure consistency of maintenance ensuring nothing is overlooked. Key equipment could have disastrous consequences for your throughput if it fails in use. Maintained equipment typically yields higher resale value.

•

*GLOSSARY Blue-sky - Creative ideas beyond current conventionalthinking.

KanBan - Japanese word for: Card Signal/Sign, a reorder trigger for production or material replenishment.

10 TIPS TO RUN A MORE EFFICIENT LABORATORY 2016 EDITION

19

GAMMA VS ETHYLENE OXIDE

(EtO) STERILISATION

Wh

en purchasing sterile laboratory products, you will notice that there are different types of sterilisation methods. Two of the most common methods are gamma sterile and ethylene oxide (EtO) sterilisation and the common questions surrounding these two types are which, if any, is better and what are the main differences.

Gamma Sterilisation Let’s first take a look at gamma sterilisation and when it is used. This type of sterilisation is an irradiation process where the product is exposed to gamma rays. This type of method is efficient, effective and relatively simple. It is a common sterilisation process as it is predictable and is able to repeated time and time again with accuracy.

Gamma sterilisation uses gamma rays that are emitted from an radioactive isotope source in order to kill any living organisms. Packaged products are subject to the sterilisation process as gamma rays have the ability to pass through packaging and the actual product itself via electromagnetic waves. This results in the packaged product being sterile and provided this package remains sealed, it will remain sterile. After the sterilisation is complete, products are able to be shipped immediately, thus, increasing the overall efficiency of this method.

When asking which sterilisation method is best, you need to identify a range of variables to determine which is best.

20

www.westlab.com.au

Ethylene Oxide (EtO or EO) Sterilisation The other common sterilisation method is EtO sterilisation which is used for products that are sensitive to radiation. EtO is a type of gas and the process involves exposing the products to the gas at a specified temperature, relative humidity, and pressure for a controlled amount of time in order to ensure proper sterilisation has taken place.

As EtO is a toxic gas which is highly explosive, organisations must comply with strict usage guidelines.

Upon completion and when the EtO gas is removed from the sterilisation room, the room then needs to be treated to remove all traces of EtO through a degassing process.

Which method is best?

When asking which sterilisation method is best, you need to identify a range of variables to determine which is best. There are many more sterilisation methods available other than gamma and EtO but most sterile packaged laboratory products fall into one of these methods. EtO sterilisation is known as the most universal sterilising method due to the fact that it can be used with almost all laboratory products including plastic and heat sensitive materials. This makes EtO a very appealing sterilisation method. It important to note that both methods work very well and usually the manufacturer will choose the most appropriate method based on the products they are sterilising. It is up to the individual to check the test methods that you are using to confirm if EtO or gamma is recommended for your processes.

WHY USE A NON-BLEEDING

pH TEST STRIP?

Wh

at exactly does it mean when we see non-bleeding test strips? Unlike common indicator papers, non-bleed is a patented technology whereby the test strips are chemically bound to the test pads. This safely prevents the dyes from bleeding into the sample which prevents contamination and allows you to continue with further analysis of the solution. You will notice that the non-bleed technology continues to work effectively even in highly alkaline solutions.

What benefits can you expect to see by using this technology?

•

A safe and reliable pH determination becomes possible even in weakly buffered solutions as the strips can be immersed until the final reaction colour has developed

•

As the test pads don’t bleed and mix, you can ensure an exact comparison to the colour scale

•

Lastly, your sample is not contaminated by indicator dyes

With ISG pH-Fix test strips, you can test the pH value quickly and easily directly at the point of interest. The strips are ready to use at any time and don’t need any calibration, set-up or maintenance. Therefore, pH determination with the ISG pH-Fix test strips is very easy, regardless of your experience or chemical background.

THE 4USE NEW ELEMENTS ON THE TABLE EDITION WHY A NON-BLEEDING PH PERIODIC TEST STRIP? 20162016 EDITION

23 21

C

orrect storage of your pH probes can substantially increase the longevity of the probe saving you time, effort, and money. Here are a few points on how to get the most out of your probes.

WHAT IS THE CORRECT WAY TO STORE A pH ELECTROCODE?

Firstly, you should make sure you always keep your pH electrode moist, the best solution to submerge the probe for long and short term storage is 4M Potassium Chloride Solution (KCl). When Potassium Chloride Solution is not available, revert to pH 4 or 7 buffer solution. Potassium Chloride Solution (also known as pH Storage Solution or Electrode Storage Solution) is available from most laboratory suppliers including Westlab.

It is also important that you do not store the pH electrodes in distilled or deionised water as this has little to no ions present and will cause the ions to leach out of the glass bulb and will render your electrode useless.

After storage, you may notice white Potassium Chloride crystals forming outside your electrode. This is normal and will not interfere with measurements.

If this has occurred, gently wash the electrode with tap water and blot dry before use being careful not to put pressure on the electrode Most electrodes are shipped with a protective cap over the glass bulb to help prevent damage in transit. Remove the rubber cap prior to using your electrode. Keep your electrode in long-term storage with the cap on, just fill the cap with enough 4M Potassium Chloride Solution to cover the glass bulb and replenish often to keep the bulb moist. Alternatively, soak a small piece of sponge in storage solution and insert into the cap. This will provide additional protection for the bulb and retain the moisture for an extended period of time.

THE 22 4 NEW www.westlab.com.au ELEMENTS ON THE PERIODIC TABLE 2016 EDITION

24

DISTILLED VS DEIONISED WATER WHAT IS THE DIFFERENCE?

T

he terms “distilled water” and “deionised water” are often misunderstood.

ing point of 100°C while other substances have different boiling points. The substance that boils at a lower temperature evaporates first. As such, the

Water Distillation Water evaporation/condensation is one of the oldest methods of producing pure water and is also known as the “Thermal Method”.

The main drawback of this method is the very high cost of the electricity needed to convert the water into steam. In the process of steam formation along with water molecules, other solutes can enter the steam according to their volatility. Evaporation is then achieved in various ways such as vacuum above the water, heating, etc.

What’s happening in the process of distillation? It is really the separation between H²0 molecules and other impurities. The water molecules have the boil-

23

www.westlab.com.au

Advantages •

High Purity outcome

Disadvantages •

High power consumption

•

High waste water component (water condenser type)

•

Slow processing time

ISG developed a Deioniser that is commonly used in Australian laboratories and has proven to be very efficient and cost effective

boiling points of various impurities is higher, and theoretically, they will begin to evaporate. The water being of lower boiling point than other impurities will evaporate first leading to the separation of pure water (distilled water)

hence they cannot remove bacteria or particulates.

Deionisation is a popular choice for general laboratory applications due to the speed, simplicity, and efficiency of the methodology.

Water Deionisation Water Deionisation filters (as known Ion Exchange, Strong Acid/Strong Base, and Nuclear Grade. These filters are fantastic for producing Ultra-Purified water for use with some of the most highly sensitive laboratory analytical instruments.

Deionisation is an on-demand process supplying purified water when needed. This is important because water at this extreme purity level degrades quickly.

Deionisation alone does not remove all types of contaminants like dissolved organic chemicals. Deionisation filters are not physical filters with a pore size,

Advantages • Low power consumption •

Low waste

•

On demand process

•

Low setup cost

ISG developed a Deioniser that is commonly used in Australian laboratories and has proven to be very efficient and cost effective

DISTILLED VS DEIONISED WATER WHAT IS THE DIFFERENCE? 2016 EDITION

24

Basic Stereo Microscopes

Zoom Stereo Microscopes

CHOOSING A MICROSCOPE (EDUCATIONAL)

2 www.westlab.com.au 25 www.westlab.com.au

Monocular Compound Microscopes

Binocular Compound Microscopes

Digital Microscopes

2. Fluorescent: a cooler bulb, which is best for viewing live specimens. The bulb is long lasting and gives an even illumination but is not as bright as tungsten.

1. Decide what specimen your students will observe?

The most standard microscope is the Compound microscope. These are used to observe specimens on microscope slides under high magnification, using either transmitted or reflected light. Stereomicroscopes are used for viewing larger objects in 3D, such as fungi, fossils, crystals, insects or micro-dissection. The magnification range is lower than the compound microscope, eg. 10x to 50x.

Skip to step 5 if you require a Stereomicroscope.

3. Halogen: found on high specification microscopes. Halogen illumination is white and extremely bright and is ideally suited to high power microscopy (1000x) Finally the light source should be focused onto the specimen. At low magnification the concave mirror focuses the light onto the stage. At higher magnification a condenser is required.

2. Decide if you require a 100x objective

If you need high magnification e.g. to view bacteria, detailed organelle structure, you will need a 100x objective lens. Most 100x objective lenses are designed for oil immersion and must have an abbe condenser and iris diaphragm to focus the light source onto the specimen.

3. Select the type of illumination you need

You have the choice of using a mirror to gather light (from a window or microscope lamp) or using built-in illumination. A mirror will suffice for low magnifications (100x) but for higher magnifications (400x) either a built-in source or lamp is required.

There are three light types: 1. Tungsten: which is the most common and least expensive. The glass envelope around the bulb darkens with age due to vaporization of the filament.

CHOOSING A MICROSCOPE (EDUCATIONAL) 2016 EDITION

4. Select either monocular, binocular or teaching head

Binocular heads offer greater comfort and less eyestrain. Choose a binocular for project work or if the viewing period is to be of long duration.

Monocular heads are available as vertical or inclined heads. Vertical is better if the user is standing and natural light is used as the illumination source. Inclined heads are more comfortable if seated.

5. Select stereomicroscope features The first choice to make is the range of magnification. Single magnification is found in the Junior stereomicroscopes. Dual magnification is offered on the WLMST05 and the WLSZ08 stereomicroscopes. The WLMST05, WLSZ08 and the WLZ6000 offer both transmitted and incident illumination. Other options include upright or inclined viewing and body size.

26

WHAT IS THE DIFFERENCE BETWEEN CONDUCTIVITY (EC) AND TDS?

W

e often see confusion arise when looking at the difference between conductivity (EC) and TDS. What is the difference?

Can they be converted? Let’s explore the two in more detail.

What is Electrical Conductivity (EC)?

Under the SI (International Systems of Units), conductivity is referred to as ‘electric conductivity’ as an international standard term but you will often just see the word ‘conductivity’ which is more commonly used. For the purpose of this article, we will refer to conductivity as EC. EC measures the ability for a material to conduct electricity meaning how well can the liquid carry an electric current through it. When looking at EC in water or liquid, we will generally find water in it’s natural state such as rain, lake water, rivers etc. will have a low level of EC (pure water has no EC). When water is subject to pollution, contamination, or impurities, we will see a change in the EC of that water as the dissolved substances increase the level of EC. As such, EC can be a good indicator of pollution in water. It is worth noting, however, that impurities such as salt in seawater for example, cause very high EC readings as the water contains a large amount of dissolved salt. This is because when

27

www.westlab.com.au

salt is dissolved, it separates into ions (electrically charged atoms).

Conductivity is usually measured in microSiemens (µS/cm) and readings generally fall between 30 µS/ cm to 2000 µS/cm. Seawater, for example, will have a reading of approximately 50,000 µS/cm. An interesting fact worth mentioning is that conductivity will actually increase when the temperature of the water increases, hence EC is commonly recorded at a 25°C with temperature and EC being recorded simultaneously. Another unit of measurement for EC is mS/cm or milliSiemens per centimeter. 1 mS/cm = 1000 µS/ cm and you will often find measurements displayed as mS/cm for higher levels of EC (i.e. 2000 µS/cm or more).

What is TDS? Total Dissolved Solids (TDS) refers to the amount of substances that have been dissolved in the liquid.

These substances can include salts, minerals, metals, calciums and other compounds which can be both organic and inorganic. In simple terms, TDS refers to anything present in the water that is not pure water and is not a suspended solid. The most commonly used method of determining TDS is measuring specific conductivity to detect the presence

of ions in water (EC). Once the EC is determined, What is the difference between EC and TDS? a conversion factor is ran (generally by the meter performing the measurement) to determine the EC is looking at how well electricity can pass through TDS. The conversion factor will differ depending on the substances that are present in the water. TDS the sample you are testing, conversion factors genis looking at the dissolved solids in the water and erally range from 0.4 - 1.0. This method, however, looks at both EC generating particles as well as paronly estimates TDS levels. For a true TDS measureticles that don’t conduct electricity which is where ment, you need to take the sample back to the labothe main difference occurs. Therefore, the EC to ratory and carry out an evaporating and weighing TDS conversion factor will change depending on the procedure. Part of the reason why the conversion contents of the sample and these conversions are from EC is not entirely accuperformed automatically by your rate is because some dissolved "While TDS can be determined TDS meter. It is important to solids may not increase the EC get the right meter suitable for from EC, the two do differ readings and won’t be picked your application. Even though it up in the measurements, there- which is why the conversion is might make sense to choose a fore, does not get converted to meter with the widest measureonly an estimate."

TDS. It’s worth noting that even ment range, this will decrease though TDS meters only provide an estimate, they the accuracy of your measurements. are fairly accurate and you will generally find a TDS In most instances EC will be measured and conmeter will be satisfactory for most applications. It verted to TDS to get an approximate TDS reading. is worth checking what level of accuracy is required TDS meters will perform this conversion automatito determine the best measurement method for cally based off a conversion factor. This factor will your individual needs. range depending on the sample being tested and it is important to choose the most appropriate meter TDS is generally measured in parts per million for your application. Most modern meters, however, (ppm) but can also be measured in mg/L. Generally, will allow you to adjust the conversion factor to help good quality water will fall between 0 and 600 ppm you get the most accurate conversion when measurand readings over 1200 ppm is often considered an ing EC. unsatisfactory level of TDS.

WHAT IS THE DIFFERENCE BETWEEN CONDUCTIVITY (EC) AND TDS? 2016 EDITION

28

7 REASONS WHY YOU SHOULD WEAR A LAB COAT LABORATORY

2 www.westlab.com.au 29 www.westlab.com.au

1. BARRIER PROTECTION - A lab coat provides substantial barrier protection and shields your torso and arms from coming into direct contact with hazardous substances in the laboratory.

2. PROTECTIVE MATERIAL - A good lab coat is semi fire retardant - The ideal material for a lab coat is 35/65 polycotton (35% polyester and 65% cotton). Polyester offers chemical resistance and ease of maintenance whilst cotton offers semi fire retardant properties.

3. PREVENTS CROSS CONTAMINATION - A lab coat prevents cross contamination – keeping your lab coat on in the lab will retain contamination within your laboratory and will reduce or prevent cross contamination into other areas.

4. FAST REMOVAL - A lab coat can be removed quickly in an emergency – If a fire or dangerous spill occurs, your lab coat (especially if it has press studs) can be pulled off in a matter of seconds to immediately bring distance between you and the hazard.

5. PROFESSIONALISE YOUR LOOK - A good clean lab coat indicates professionalism and distinguishes a laboratory individual as a specialist in their field.

6. SAFER WORK SPACE - A lab coat with an elastic cuff will assist with keeping your sleeves out of your experiment and keep you in control of your workspace. It will also protect your arms from potential hazardous splashes.

7. CLOTHING PROTECTION - A Lab coat will protect your regular clothing from dust, dirt and non-obvious contamination in the laboratory.

Good Quality 65/35 Polycotton lab coats with elasticised cuffs and press-studs are available at: www.westlab.com.au

7 REASONS WHY YOU SHOULD WEAR A LAB COAT LABORATORY 2016 EDITION

30

PURCHASING ETHANOL IN

AUSTRALIA

S

ome grades of Ethanol are restricted in Australia under the the concessional spirits scheme. In order to purchase these chemicals, you are required to meet certain criteria which may require you to obtain a permit.

Why is ethanol restricted?

The reason why ethanol is a restricted product is due to its alcohol nature. Ethanol (in a diluted form) is present in alcoholic drinks and for obvious reasons, can be a problem if obtained and used for human consumption. You will come across both undenatured and denatured ethanol and it is important you are well aware of the differences.

•

•

31

Undenatured Ethanol - This type of ethanol needs to be restricted to entities that meet certain criteria (outlined in the next section) due to it being of pure nature with no additives or denaturants. This type of ethanol could be used for human ingestion hence the restriction Denatured Ethanol - This type of ethanol has undergone a process to simply make it un-

www.westlab.com.au

drinkable and therefore, is not restricted. This denaturing process does not alter the ethanol molecule, instead, the ethanol gets mixed with poisonous chemicals so that it cannot be used for consumption.

The restriction on ethanol is different to the restriction on drug precursors. Drug precursors are chemicals that can be used to make illicit drugs and require an End User Declaration (EUD) to be completed prior to purchase and relevant checks performed by your state police force. Ethanol, on the other hand, has a different type of restriction to drug precursors which comes under the concessional spirits scheme. In order to purchase ethanol, you require a permit that is obtained from and managed by the Australian Taxation Office (ATO).

Who can purchase ethanol?

Your supplier will require an ongoing permit to be able to sell ethanol and depending on the type of permit, it may last up to five years. Your supplier will have restrictions in place for supplying ethanol as per the ATO requirements.

In order for your supplier to supply ethanol to you, you must meet any of the below criteria:

•

•

You (person or entity) hold a current concessional spirits permit and the nominated supplier on that permit matches the actual supplier (you can specify up to 4 suppliers on your application).

Note that your supplier cannot supply more than the quantity that is specified on your permit.

You (person or entity) fall into one of the below categories of professionals and institutions:

I need a permit, how do I get one?

The ATO requires you to complete an application form to receive a permit to purchase concessional spirits. This application form requires you to fill out details of the applicant, details of the spirits required, and details of your licensed supplier(s). The form needs to be lodged with the ATO and they aim to process your application within 28 calendar days.

Once your application has been processed and approved, you will require to provide your supplier with a copy of your permit before they can supply you with the spirits.

o Health care practitioners (pharmacist, doc-

tor, chiropractor, dentist, osteopath, physiotherapist, or registered nurse)

o Veterinary practitioners o Medical, government, and educational insti-

tutions

PURCHASING ETHANOL IN AUSTRALIA 2016 EDITION

32

TIPS TO PROPERLY CARE FOR YOUR MICROSCOPE

M

icroscopes can be really expensive, especially when you enter into the industrial range of high-end microscopes where you can expect to see prices in excess of $20,000. They are a significant investment to any laboratory and proper care and maintenance is paramount to ensure your microscope stands the test of time. We’ve analysed our top tips to properly care for your microscope.

Storage - When storing your microscope, make sure that it is protected from dust, dirt, pollen, lint etc. with a good Westlab dust cover. Leaving a microscope out in the open can cause the image quality to deteriorate over time. It is a good idea to unplug the microscope from power while in storage and remove oil from the oilimmersion objective with a delicate task wipe such as a Kimwipe or Westlab’s Delicate Task Wipes. Storing your microscope in a cool, dry place also will help to prolong the life of your

33

www.westlab.com.au

microscope. Keep it clear from any potential chemical fumes as these can be detrimental to the lenses and other metal parts.

Lens and Objective Care - Microscope lenses are very fragile and need to be handled with care to prevent scratches. Never let your lens touch the microscope slide and never touch any of the lens with your fingers. Microscope lenses are difficult to clean and proper care is very important. To determine which of your objective lenses need to be cleaned, take a clean glass slide and put it under your microscope, when the microscope is focused you will be able to move the slide around and determine if the visible dust is moving with the slide or staying in the same place (this means the dust is on the objective lens).

Immersion Oil - Immersion oil is essential for good optical performance of your microscope.

It is important that you use the oil correctly and

Caring for your microscope is important to maximise your return on investment.It is important that you choose a microscope that has the structural integrity and quality to stand up to a long term maintenance program.

make sure that you remove the oil after each use. Failure to do so can result in the oil making its way into into mechanisms that will cause damage to the microscope and sometimes this damage can be irreversible. Removing immersion oil is best done with a lens tissue and used very gently.

Annual Service Check - On an annual basis it is a good idea to clean and lubricate moving parts of the microscope. Inspect the power cords and plug and ensure no exposed wires and stock up on replacement light bulbs, if you are using a microscope with LED lighting you will not be required to change the globe as they should last for over 40,000 hours.

of microscope you have, you may need to have it serviced more frequently.

Caring for your microscope is important to maximise your return on investment.It is important that you choose a microscope that has the structural integrity and quality to stand up to a long term maintenance program. Remember the old saying “A stitch in time saves nine!” make sure you address issues immediately to eliminate downtime and increase the lifespan of your microscopes. Westlab has a range of accessories in the links below that will assist you with the correct care techniques.

Servicing - It is recommended that you get your microscope periodically tested by a qualified servicing technician. Generally, a service is required after 200 hours or every 3 years, whichever comes first. Depending on the type

TIPS TO PROPERLY CARE FOR YOUR MICROSCOPE 2016 EDITION

34

DANGEROUS GOODS STORAGE IN THE LABORATORY Ensuring you are keeping compliant with Australian Standards will ensure that you are working in and providing a safe working environment. For more information on the storage of dangerous goods, you can refer to the relevant Australian Standards (purchase required) or the National Code of Practice.

D

angerous Goods Cabinets are a method of storing chemicals or substances that are classified as unsafe if improperly used.

Dangerous goods can cause some serious health problems if used improperly. It is important that they are stored and used correctly to ensure a safe working environment is provided for everyone.

AS 1940-2004 refers to The Storage and Handling of Flammable and Combustible Liquids and is commonly referred to as the standard for dangerous goods cabinets. There is a more specific standard to storing chemicals in the laboratory which provides more specific information for a laboratory application. AS/NZS 2243.10-2004 is the standard referring to Safety in Laboratories - Storage of Chemicals and outlines some requirements you need to follow for dangerous goods cabinets in your laboratory as outlined below.

• Cabinet Storage Capacity - If you are storing Classes 4.1, 4.2, 4.3, 5.1, or 5.2, the capacity of a storage cabinet shall not exceed 50L. For all other chemicals, the capacity shall not exceed 250L.

• Cabinet Separation (applies to working laboratory spaces only) - The cabinet storage capacity of all cabinets in a 10m radius shall not exceed 250L or 250kg. For example, you cannot have two 250L cabinets side-by-side but you

35

www.westlab.com.au

can have two 100L cabinets side-by-side. Additional to this, you can’t have more than 10L or 10kg each of dangerous goods of Classes 4.1, 4.2, 4.3, 5.1, or 5.2 that are classified as PG I in that 10m radius. The radius is measured horizontally and will measure through walls unless these walls are able to prevent the spreading of a fire (you will need to take into account the magnitude of the potential fire when determining if a wall breaks up this radius). This requirement only applies for cabinets located within a laboratory and does does not refer to other storage areas such as a chemical store.

• Design - When purchasing a dangerous goods cabinets, ensure that it meets the design requirements outlined in AS 1940 by asking your supplier prior to purchase. You should not purchase any cabinet that is not compliant. Another important aspect worth noting is that if you intend on storing Class 5.2 dangerous goods in the cabinet, the cabinet must have a door closing mechanism that allows the door to open and release pressure caused by accelerated decomposition. Some cabinets, such as the Modulab 4-IN1 cabinets have the provision to lock the handle in the open position so that the door will still

close automatically but won’t latch when closed.

• Location- In addition to cabinet separation as mentioned earlier, a dangerous goods cabinets has some additional requirement in regards to location. o Cabinets should not be located above one

another

o Cabinets shall be located so that it does not

interfere with escape in an emergency (minimum of 3m is recommended between cabinets and escape doors)

o Cabinets should not be located under stairs

or in corridors

o Cabinets shall not be closer than 3m to an

ignition source other than ceiling lights unless you have carried out a hazardous zone assessment in accordance with AS 2430.1 (only if the cabinets contain flammable liquids or substances that can release flammable or fire-promoting vapours or gases).

•

mable or fire-promoting vapours or gases).

Labelling - The doors of a dangerous goods storage cabinet needs to display signage so that the contents of the goods can easily be determined. The cabinets require the ADG Code (Australian Dangerous Goods Code) class labels to be displayed on the doors. This will not switch to the new GHS labels and you should not place GHS labels on your cabinets. It is unclear if the GHS will be a requirement on cabinets in the future but as the GHS pictograms are more of a generic label and that multiple ADG labels can represent just a single GHS label, the GHS labels are unable to provide as specific details of the contents of the cabinet than what the ADG Code labels can.

Ensuring you are keeping compliant with Australian Standards will ensure that you are working in and providing a safe working environment. For more information on the storage of dangerous goods, you can refer to the relevant Australian Standards (purchase required) or the National Code of Practice.

Some cabinets, such as the Modulab 4-IN-1 cabinets have the provision to lock the handle in the open position so that the door will still close automatically but won’t latch when closed.

DANGEROUS GOOD STORAGE IN THE LABORATORY 2016 EDITION

36

THE STEM GLOBAL MOVEMENT STEM does not simply refer to teaching of those disciplines, but also looks at a different approach in the way they are taught. STEM focuses on creating an environment where students can solve real-world problems using their creativity.

W

ith the topic of STEM (Science, Technology, Engineering, and Mathematics) gaining a lot of traction globally of late, we thought this would be a good opportunity to take a look into the initiative and the explore how this will affect the education industry.

What is STEM? STEM is a global initiative where countries such as the USA, Canada, Australia, Turkey, Singapore and more developing programs to support STEM learning. The topic of STEM (in the sense of curriculum) first came to light in the early 2000s where the National Science Foundation in the US were creating curricula for the disciplines of science, technology, engineering, and maths. At this time, the acronym was SMET but Judith A. Ramaley, who was the assistant director for education and human resources at the time, didn’t like the sound of SMET so she changed it to the acronym we now all know as, STEM. So why is STEM such an important topic? It has become apparent in our fast paced society that the future requires more skills and knowledge in the STEM disciplines to cope with our rapid technologically advancing economy. There is becoming an increasing demand for workers who are creative problem solvers using new and innovative technologies. Young Australian’s in the education system are currently not gaining the STEM skills needed for the future economy and employers are finding it hard to locate candidates with the relevant expertise to fill their STEM related roles. This demand is only going

37

www.westlab.com.au

to increase at an exponential rate.

"THE GLOBAL ECONOMY IS CHANGING. NEW TECHNOLOGIES AND SMART COMPANIES LEAD. NEW INDUSTRIES AND NEW SOURCES OF WEALTH ARE EMERGING. NEW SKILLS ARE REQUIRED FOR WORKERS AT ALL LEVELS...AT THE CORE OF ALMOST EVERY AGENDA IS A FOCUS ON STEM: SCIENCE, TECHNOLOGY, ENGINEERING AND MATHEMATICS." Professor Ian Chubb AC I Chief Scientist of Australia (23/05/2011 to 22/01/2016).

STEM does not simply refer to teaching of those disciplines, but also looks at a different approach in the way they are taught. STEM focuses on creating an environment where students can solve real-world problems using their creativity. It takes the focus off the traditional style of education and looks at a new approach where students are able to explore the subject with the same thinking that will be required in our future economy. You cannot automate creativity which is why it is paramount that we grasp this concept and work towards future-proofing the next generation workforce.

STEM in Australia While the STEM movement emerged from the US, Australia adopted the initiative and began developing programs to invest in Australia’s educational future in STEM. It was deemed an integral part of the overall economic strategy and required we act as a

matter of urgency. Research is now indicating that as much as 75% of the fastest growing occupations now require STEM related skills and knowledge.

In December of 2015, the Education Council who is a representative of the Australian Government released a strategy called the National STEM School Education Strategy. This strategy was endorsed by Australian Education Ministers and was the first real strategy Australia had released as a nation. The strategy set out to achieve two main goals: 1. To ensure all students finish school with strong foundational knowledge in STEM and related skills 2. To ensure that students are inspired to take on more challenging STEM subjects With these goals in mind, the strategy identified five areas requiring national action in the view of achieving the greatest leverage in our education system.

•

Increase student STEM ability, engagement, participation and aspiration

•

Increasing teacher capacity and STEM teaching quality

•

Supporting STEM education opportunities within school systems

•

Facilitating effective partnerships with tertiary education providers, business and industry

•

Building a strong evidence base

THE STEM GLOBAL MOVEMENT 2016 EDITION

We are also now beginning to see state governments releasing plans and strategies on how they will accommodate STEM in education. Victoria, for example, has released a state plan for STEM which will see over $300 million invested into STEM initiatives that range from new tech schools through to professional learning programs. Over the next 3 years, the South Australian Government will also invest $250 million into schools for refurbishments and new facilities as part of STEM Works. We are seeing other states and territories adopting similar plans and strategies.

The Future of STEM There’s no doubt about it, the world is changing at a rapid rate. The need for change is becoming a pressing issue and it’s important that we adapt in order to not only keep up with the rest of the world, but lead it.

We will inevitably see drastic changes in our education and training system over the next decade. New technologies will begin to make their way into the classroom to provide better learning experiences.

We will see new types of facilities being built to solely accommodate STEM learning which will be notably different to any type of facility we have seen in the past. STEM will be more and more integrated into our school systems and we may even see incentives come into play for students to pursue further STEM studies. It is difficult to imagine a world in 10 years time, especially when you realise that the iPhone didn’t even exist 10 years ago! What we know for sure is that huge changes will be taking place in response to the STEM movement, especially in the education system. It’s important that we embrace this change so that together, we can create a better future for everyone.

38

THE DIFFERENCE BETWEEN

A LAB OVEN AND A DRYING OVEN

2 www.westlab.com.au 39 www.westlab.com.au

If

you are ever in the market for an oven for your laboratory, you will likely come across standard lab ovens and drying ovens. It can be a common misconception that both these types of ovens are the same but they are actually two different pieces of equipment.

Drying Oven

that is lacking in a laboratory oven. A drying oven requires an airflow system that can extract moisture from the air and depending on your requirements, may or may not be required.

Laboratory Oven

A Drying oven is designed to remove moisture from the oven chamber so to dry the samples as quickly as possible. The drying oven process introduces fresh dry air to the chamber and expels the warm moist air simultaneously allowing to rapidly dry the samples. A drying oven provides high performance drying and heating. You will notice that drying ovens will be more expensive than a standard laboratory oven mainly due to the oven having drying capability

A laboratory oven, on the other hand, is designed to heat samples only. Unlike a drying oven, a lab oven will recirculate the same air around in the chamber.

As a result, a lab oven will provide heating only. Laboratory ovens are a more cost effective option over a drying oven and will be a suitable option if you are only requiring heating functionality. You will likely notice that a lab oven will have a higher temperature range than a drying oven so be sure that the oven you choose is capable of reaching your required temperatures.

DRYING OVEN Fresh dry air is drawn into the unit, mixed with hot air and passed over each shelf. Hot moist is expelled through a vent at the top of the unit.

LAB OVEN Air is recirculated around the chamber and passed over individual shelves. No fresh air is drawn into the chamber.

THE DIFFERENCE BETWEEN A LAB OVEN AND A DRYING OVEN 2016 EDITION

40

WHAT YOU NEED TO KNOW BEFORE PURCHASING A DUCTED FUME HOOD

Requiring a Ducted Fume Hood? Contact us for a proposal, we can also provide commissioning services - 1800 358 101 or sales@westlab.com.au.

D

ucted Fume Hoods are the traditional type of fume hoods and are fixed in position with a ducted system in place so that fumes are expelled up through the ducts and out of the building. As this type of fume hood also requires services such as ductwork, exhaust fans, and mechanical systems, you can see how the setup of a ducted fume hood is a significant investment. There are a few considerations that you should take into account before making a purchase of a ducted fume hood. For the purpose of this article, fume hood refers to a ducted fume hood. Ductless fume hoods are beyond the scope of this article and will be covered separately at a later stage.

Location of Fume Hoods The location of a fume hood is something that needs to be considered prior to purchase. Australian Standards AS/NZS 2243.8:2006 outlines positioning requirements of fume hoods in a laboratory. In positioning a fume hood, you need to take into consideration the below requirements: •

41

Proximity to traffic areas - There needs to be at least 1m between the sash (which is the protective barrier between the experiment and the researcher) and any traffic area. This means that there should be a 1m undisturbed zone between

www.westlab.com.au

the sash and the traffic area. In saying that, the standards also state that if the laboratory traffic area is in frequent or continual use, the minimum distance of the traffic area should be 3m.

• Proximity to bench tops - If the fume hood is near an opposing bench top, a minimum distance between the sash and the bench top should be at least 1.5m. This is applicable where the same operator is using both the fume hood and the bench top or where only occasional traffic is anticipated.

• Proximity to walls, other obstructions, and other operators - An opposing wall, other major obstruction, or an opposing bench used by another operator must not be within 1.8m of the sash.

• Proximity to architectural obstacles o Walls or similar - a fume hood should not be closer than 300mm from each side of the fume hood to a wall or similar smooth obstruction that extends past the line of the face of the fume cupboard. o Other obstructions - obstructions should not have the face of the column in front of the plane of sash.

o Doorways - a doorway should not be within

1.5m of the sash or should not be within 1m from the side of the fume hood. o Maintenance access - a fume hood should have adequate access for maintenance as specified by the manufacturer’s requirements.

Commissioning of Fume Hoods To be compliant with AS/NZS 2243.8:2006, commissioning testing must be carried out in accordance with Australian Standards to ensure proper functionality and proper ventilation. The commissioning tests will need to include a smoke test, face velocity, noise level, and illuminance. AS/NZS 2243.8:2006 outlines all requirements of commissioning testing in detail and states that testing shall only be carried out by a competent person. Results of the test need to be recorded with copies available with the operating and maintenance manuals. It is also important to supply a copy of the test results to laboratory managers.

Maintenance of Fume Hoods On top of commissioning your fume hood, it is important that you subject your fume hood to regu-

lar maintenance and testing. When maintenance is occurring, the fume hood should be removed from a power source and tagged ‘system under maintenance-do not use’. All chemicals should also be removed from the fume hood whilst maintenance testing is being conducted. Six-monthly, and annually maintenance checks should be conducted on fume hoods as outlined in AS/NZS 2243.8:2006 and reports of the maintenance checks should be submitted to the laboratory manager. Weekly checks may also be required if you have air cleaning devices installed.

A ducted fume hood is a significant investment for any laboratory. It is important that you plan where it will be situated prior to purchase to ensure that you are in accordance with Australian Standards. Be sure to keep in mind what will be required for installation and that you have arranged commissioning by a competent person upon installation. By planning the installation of a fume hood upfront and including all the additional areas that require consideration, you will have an understanding of all costs upfront as well as all components of an installation. This will ensure that you enjoy a smooth installation process and that no hidden costs occur throughout the project. For more information, you can download a copy of the relevant Australian Standards (purchase required).

Requiring a Ducted Fume Hood? Contact us for a proposal, we can also provide commissioning services - 1800 358 101 or sales@westlab.com.au.

WHAT YOU NEED TO KNOW BEFORE PURCHASING A DUCTED FUME HOOD 2016 EDITION

42

A GUIDE TO CHOOSING A

PIPETTE TIP It is worth taking the time to choose a suitable tip as it will not only save you money but also ensure maximum accuracy.

T

here are an array of pipette tips available in the market and it can become difficult to select an appropriate tip for your application.

Not only do you need to find a tip that fits your pipette, you also need to decide on the type of tip and the quality of the tip. We’ve compiled a list of items that will help you choose the right tips for your laboratory.

way up into the pipette helping to prevent cross contamination.

• Gel-Loading Tips - these tips are ideal for use with SDS gels or agarose samples. They are generally longer tips and allow for easy loading of gel electrophoresis samples.

Firstly, it’s worth mentioning the four most common type of pipette tips that are used in laboratories to provide a base for the latter discussion points.

Quality really comes into play when selecting a pipette tip. It doesn’t matter how good your pipette is, without the right pipette tip, you won’t be getting the results you require. Pipette tips vary greatly between manufacturers. Here are a few key areas that should be considered when selecting a tip:

Standard Tips - these are your standard pipette tips. You will find, however, that most standard pipette tip users are now moving to low retention tips.

• Low Retention Tips - these tips have an inner surface specially developed to keep sample binding to a minimum. This ensures maximum recovery of the sample resulting in high accuracy.

•

•

43

Filter Tips - these types of tips are used to protect the pipette from aerosols making their

www.westlab.com.au

•

Material - a good pipette tip will be made from high quality virgin polypropylene. Beware of plastic and/or metal additives that are commonly found in blue and yellow tips as these additives can contaminate samples. If you are selecting a filtered tip, be sure the filter is made from polyethylene and also free from additives such as cellulose.

Mold Quality - pipette tips are made by an injection molding machine. The outcome of the pipette tip is based on the design of the mold and the quality of the polypropylene being injected into the mold • Contaminant Free - ensure that you only purchase tips that have been certified to be free of RNase, DNase, DNA, Pyrogen, PCR Inhibitors, and ATP. This is even more important if you are performing sensitive microbiological testing.

• Fit/Compatibility - not all pipette tips will fit your pipettor. It is important to ensure that the tip you are considering will fit your pipettors. You shouldn’t have to force the tip onto the pipette, it should grab and stay in place with little to no force required. Most pipette tip brands will have a compatibility chart which will help you to choose an appropriate tip. Most tips, however, •

Q

should be compatible with almost all the popular brands of pipettors around the world.

Low Retention - low retention tips are becoming more and more popular in recent years. They are generally regarded as a premium tip and you can expect to pay more for them. When looking at low retention tips, ensure that the tips have no secondary process during manufacturing that can cause compounds leaching from the tip during use such as silicone coating.

nce you have identified a pipette tip that will work O

best for your application, ensure you request samples from your potential supplier before purchasing in bulk lots. This will just make sure that they meet all of your required needs including checking that they fit your pipettes correctly. It is worth taking the time to choose a suitable tip as it will not only save you money but also ensure maximum accuracy.

uality really comes into play when selecting a pipette tip. It doesn’t matter how good your pipette is, without the right pipette tip, you won’t be getting the results you require.

A GUIDE TO CHOOSING A PIPETTE TIP 2016 EDITION

44

MEASURING MELTING POINT

T

he determination of a melting point of a sample is a standard laboratory procedure and is relatively straightforward. It is used to identify a sample, establish its purity, and determine the thermal stability of the sample. When measuring a melting point, you will generally find that it is recorded as a melting range rather than the exact melting point. This is due to most samples appear to melt over a small temperature range. A melting range is the difference between the temperature at which the sample begins to melt and the temperature at which the sample has actually melted.

Methods of Measuring Melting Point There are a variety of methods that you can use to determine the melting point of a sample. The most common and most basic method of determination is the capillary method. This method involves placing the sample in a capillary tube and running an experiment that will heat the sample until it reaches melting point. The melting point can then be recorded.

There are a few ways in which you can setup an ex-

45 www.westlab.com.au

periment with the capillary method. The first is a manual apparatus setup with the aim of heating up a sample inside a capillary tube whilst visually looking for when the sample has melted. The concept involves placing a small amount of the substance in a capillary tube and joining this to a thermometer.

The capillary tube is then placed into a heating bath and the experiment is conducted. If you don’t have a heating bath, you can use Mineral Oil in a Thiele Tube and heat the tube with a Bunsen Burner. It is important to heat the sample slowly using this method so that a thermal equilibrium can be established.

A more modern way of using the capillary method is to use a device called a Melting Point Apparatus. This device uses the same concept of heating a sample in a capillary tube but makes the process far more simpler and quicker. There are many different types of Melting Point Apparatus machines and they range in functionality and accuracy. At a basic level, the machine is designed so that a capillary tube with the sample can be inserted into the device and rapidly heated to a set temperature. Generally, you will heat the capillary tube to near melting point and then decrease the speed of the temperature

When measuring a melting point, you will generally find that it is recorded as a melting range rather than the exact melting point. This is due to most samples appear to melt over a small temperature range. increase so that you can observe when the sample melts. Observation is generally conducted through a viewing eyepiece. A Melting Point Apparatus will more than likely have the temperature displayed in digital format for easy recording of data.

Sample Preparation Firstly, you must ensure that the sample is fully dry and in powdered form. Then with your capillary tube, use the open end of the tube to press down gently on the sample several times. You then need to get the powder all the way to the bottom of the capillary tube by tapping the closed end multiple times on a hard surface so that the sample is compacted down at the closed end of the tube (you could also use a method where you drop the tube multiple times through a glass tube approx. 1m in length). For further accuracy, you can use a packing wire to further compact the sample. Note that the sample height should be between 2 and 3mm to ensure best results.

Melting Point Tips Here are a few helpful tips to assist with melting point experiments.

•

Never re-melt a sample! Always use a fresh sample and a new capillary tube.

•

Always use the same batch of capillary tubes for routine measurements. Not all capillary tubes are equal and using the same batch will ensure repeatable results.

•

Always clean the tube before running the melting point experiment. Failure to do so can result in a low melting point or a wide melting range.

•

Don’t heat the sample too fast. It is recommended only 1-2°C per minute.

N ever re-melt a sample! Always use a fresh sample and a new capillary tube.

MEASURING MELTING POINT 2016 EDITION

46

MEASUREMENT OF PH

IN PLANT TISSUE

I

t is often necessary to measure the pH of plant tissue to determine plant health.

Where pH values are above 6.4, plants can be prone to insect attacks and specific diseases, thus an optimal pH of 6.4 is desired. Whilst laboratory soil and tissue tests are beneficial tools, they often do not yield results for days or weeks.

We can thus use an alternate method of diagnosing plant health using certain types of pH meters. The LAQUAtwin pH meter, for example, can be used to determine the pH of plant tissue providing an easy and quick method to determine if plant tissue is at an optimum pH.

Method To measure, take a few leaves, roll them into a tight ball and squeeze out a few drops of sap using a garlic press. Be sure to use a good quality stainless steel garlic press. Generally, the mature leaves of the plant give the most accurate picture of the plant’s health. You can then use a meter such as the LAQUAtwin pH meter to run the test. With this method, the plant tissue has sufficient moisture in order to pH 8.0

N, P, S, shortags

Neutral 7.0

60%

Ideal

no risk 60%

Cation problem Ca, Mg, K, Na shortage

70%

47 www.westlab.com.au

90% 100%

4.0

•

If the pH is >0.5 higher than 6.4, add a small amount of phosphate fertilizer.

•

If the pH is >0.5 lower than 6.4, add a small amount of calcium/potassium fertilizer.

After a week, repeat the test; ensure the pH of the plant tissue is close to pH 6.4 for optimal plant health.

Ensuring an optimal pH of 6.4 in plant tissue will encourage healthy plant growth and prevent insects and diseases attacking the plant. If you can find a small compact meter that has the ability to conduct this test, it will provide you with a convenient and simple solution that can be carried around in your pocket for easy on-site testing.

100% 90%

5.0

If the pH value is more than 0.5 away from the optimal 6.4 value, adjustments can be made to bring the plant tissue back to the optimal value:

Risks

Anion Problem

6.4 6.0

provide a reading when placed on the sensor.

% of insect attack probability

% of insect attack probability

insect weakens tissue ph drops on localized tissue spots Disease attacks

3 THINGS TO CONSIDER WHEN CHOOSING A CENTRIFUGE TUBE

C

entrifuge tubes range a lot in terms of quality and performance. There are multiple factors that contribute to the overall quality of the tube that we will discuss in this article. It’s important to take into account your own requirements of a tube and then choose a tube that is going to best suit these requirements.

Relative Centrifugal Force A centrifuge tube will have a maximum speed rating at which the tube can withstand. The speed capacities of tubes will vary greatly between brands so it is important to determine what speeds you will require and go for a tube that will be able to withstand these speeds. When looking at speeds, it is best to look at RCF rather than RPM as RCF takes into account the gravitational force being applied. RPM, on the other hand, only takes into account the rotors spinning speed.

Pricing can vary depending on the maximum RCF a tube can handle so firstly, work out the RCF you will require and find a tube that fits to these requirements. If you are not dealing with high speeds, you may be able to choose a tube with a lower RCF to save on costs of the tubes. If you are a volume user, any potential savings on the tubes can add up to a sizeable amount over time.

Chemical Compatibility Depending on the type of material the centrifuge tube is made out of, it will obviously have different resistance capabilities to different chemicals. It is important to take into account the types of chemicals you will be using and ensure that the tube you

choose has satisfactory resistance to these chemicals. Centrifuge tubes are available in an array of materials such as polypropylene (PP), polyallomer (PA), polycarbonate (PC), and polyethylene terephthalate (PET). PP is a popular type of tube due to its ability to be used for high speed applications, is autoclavable, and is resistance to most organic solvents. Be sure to check a chemical resistance chart to determine what tube will be most suitable for your laboratory.

Volume Note that you should never overfill a centrifuge tube as it can cause leakages. The maximum you should ever fill a centrifuge tube is ¾ full. Some ultracentrifuge tubes, however, must be filled to the top to prevent collapse. You also need to ensure that you don’t underfill the tubes either. It is always best to make sure you check the product specifications from the manufacturer as they will provide filling guidelines.

With this is mind, the tube you select will need to be based on the volume you will be using. If you find that the tube most suitable for the volume you are using will not fit the rotor capacity of your centrifuge then consider an adapter for the rotor. Most manufacturers will have these adapters available so speak to your supplier about an adapter to suit your needs.

A centrifuge tube is an important consumable in any laboratory and the decision upon what tube will best suit your laboratory should not be taken lightly.

Suppliers will be able to provide samples for testing prior to committing to order. This gives you the opportunity to put the tube through its paces to ensure that it performs. If you can, get a few different brands to sample and run the same tests on each, this will further assist you in making your decision.

3 THINGS TO CONSIDER WHEN CHOOSING A CENTRIFUGE TUBE 2016 EDITION

48

WHAT IS THE CLEAN-IN-PLACE

(CIP) METHOD?

C

tions can be monitored by a specific or nonspecific lean-in-place (CIP) is a method of cleaning analytical method. Specific methods that detect the the interior surfaces of pipes, vessels, proindividual ingredients of cleaning solutions are ion cess equipment, filters and associated fitselective electrode (ISE), high performance liquid tings without disassembly. The CIP system chromatography (HPLC), thin layer chromatography is run by a digital computer called programmable (TLC), flame photometry, and ultraviolet spectroscologic controllers (PLCs) to control the flow, tempy. Non-specific methods that detect the presence perature, and time for the chemical solutions, which of blend of ingredients are pH, conductivity, and total could be acidic, alkaline or sometimes both, to organic carbon (TOC). Specific methods are usually achieve maximum cleaning. The chemical solutions preferable by regulatory are circulated through agencies, but they may a circuit of tanks and/or THE CIP SYSTEM IS RUN BY A DIGITAL accept non-specific methlines to eliminate contamiods with adequate rationants or product residues COMPUTER CALED PROGRAMMABLE LOGIC nales for their use. and are rinsed out with water. Depending on the CONTROLLERS (PLCs) TO CONTROL THE FLOW, CIP system, chemical soAs CIP offers fast, repeatTEMPERATURE, AND TIME FOR THE CHEMICAL lutions may flow back to a able, and effective cleanreservoir so that they can ing without chemical exbe re-used or drained im- SOLUTIONS , TO ACHIEVE MAXIMUM CLEANING. posure risk to people, it mediately after they have is utilised in industries been used. that require high levels of hygiene such as dairy, beverage, processed foods, pharmaceutical, and cosmetics. CIP is typically emAfter CIP, the equipment should be visibly clean and ployed for cleaning bioreactors, fermenters, mix free from chemical residues. The final water rinse vessels and other equipment in manufacturing famust ensure that chemical residues are removed cilities and many CIP systems use alkaline cleaning properly. Chemical residues from cleaning solu-

49 www.westlab.com.au

Cleaning validation is a critical part of current good manufacturing practice to ensure that production materials that come in contact with equipment surfaces are not contaminated.

solutions containing 0.5 to 2% (by weight) caustic soda or sodium hydroxide (NaOH) to remove fats and proteins.

Sodium Testing You can use a sodium meter to measure and monitor residual sodium ion (Na+) concentration during CIP in process plants. This will help you to gain an accurate measurement that will complement the cleaning efficiency of CIP. Using a sodium meter (such as the LAQUAtwin B-722 sodium ion meter), calibrate the meter according to manufacturer’s instructions. Rinse Water Sampling and Wipe Sampling are two sampling methods for measuring cleaning chemical residues (a combination of these is desirable). Rinse Water Sampling involves taking a sample of an equilibrated water rinse (usually water for injection or pure water) that has been recirculated over all surfaces.

To measure, place drops of rinse water sample onto the sodium ion sensor using a pipette. Alternatively,

open the sensor guard and soak the sensor into a beaker containing rinse water. Swab or wipe sampling is done directly on equipment surfaces. This is performed in order to assure that the residues are being adequately detected and not simply sitting on the surface and not being dissolved into the equilibrated rinse water. Before wiping begins, moisten the sampling sheet (usually sold separately) with water for injection or pure water and allow the equipment to dry after the cleaning procedure. Then wipe the surface with a moistened sampling sheet and place it onto the sensor. A blank preparation is required for this sampling method.

Results and Benefits Cleaning validation is a critical part of current good manufacturing practice to ensure that production materials that come in contact with equipment surfaces are not contaminated. The pre-rinse, alkali circulation, and other steps must take place in correct order. Checks on the identity, purity and strength of cleaning chemicals and on quality of water used for rinsing are needed. Also, the validation protocol must include testing for the residual cleaning chemical to ensure that cleaning chemical used is properly removed. The analysis must be quantitative and the acceptance criteria are determined according to regulatory guidelines and company policy.Â

WHAT IS THE CLEAN-IN-PLACE (CIP) METHOD? 2016 EDITION

50

SPARKLING GLASSWARE WITHOUT THE SIDE EFFECTS

If possible, it is best if you replace your harmful cleaning solution with a safe alternative. You want to look for something that is non-toxic, non-corrosive, and is readily biodegradable.

W

hen it comes to your laboratory, superior cleaning power is required that simply cannot be achieved with your standard domestic products. Specialised laboratory decontaminants and cleaners are available to give you excellent performance. These types of cleaning products go far above and beyond the power of standard domestic cleaning products and as you would expect, you’ll have to pay more for them.

There are a huge amount of laboratory cleaners available in the market today. It can often be confusing as to what cleaner is going to be most suitable for your laboratory. The biggest factor to consider which is often overlooked is the safety component. Yes, you read that right! Safety is an area that is important to consider. What do we mean by safety? Labs can use a large volume of cleaning solutions throughout the year. When we say safety, we mean how harmful is the product you are using. Skin irritation can occur when nasty chemicals come into contact with the skin, this can result in Contact Dermatitis causing immediate and long-term problems.

There is a couple of ways to combat skin irritation.

51 www.westlab.com.au

Firstly, you can protect yourself from the substances by wearing PPE such as gloves and aprons. Be sure to make sure that the material of your PPE is resistant to the types of substances it will come into contact with. This measure of protection does work but is the least effective method in terms of hierarchy of control. The most effective method would be to eliminate the harmful substance.

If possible, it is best if you replace your harmful cleaning solution with a safe alternative. You want to look for something that is non-toxic, non-corrosive, and is readily biodegradable. Arguments have stated that performance wise, a non-toxic solution wouldn’t achieve the level of cleaning required, but this is simply not the case anymore. There are safe options out there that match, and in some cases outperform their toxic counterparts. In terms of pricing, non-toxic solutions are generally more expensive, however, we are seeing some brands coming in at a similar price point making it an easier decision to make the switch. If you’re looking at switching to a non-toxic solution, try requesting samples from suppliers. This will give you an opportunity to test it out and make sure it stands up to the task!

ORDERING WITH WESTLAB IS EASY...

ONLINE www.westlab.com.au

PHONE 1800 358 101

EMAIL sales@westlab.com.au

FAX 1300 725 903