Chapter 3 Hazardous materials
School Science Laboratory Safety Regulations
must be avoided, for example, jerky motion, shaking the loop and agitating the liquid. A contaminated loop, when placed immediately into a flame for sterilisation, may also produce an aerosol through volatilisation. To prevent aerosol production, use disposable loops. k.
The lids of Petri dishes should be opened only just enough to allow the inoculating tool to be manipulated and for as short a time as possible.
I.
Petri dishes should be incubated in avoid condensation dripping onto cultures.
an
inverted
position
to
m. During incubation, the lid of the Petri dish should be secured to the base with tape or paraffin film so that the lid cannot be accidentally removed. ?.
Yeast cultures generate considerable quantities dioxide gas. Therefore, the incubation containers plugged with cotton wool to allow excess gas to escape.
of carbon should be
3.2.4. Recombinant DNA involving microorganisms a.
All recombinant DNA (rDNA) technology studies involving RG-I microorganisms and RG-I host vector systems may be conducted in a BSL-1 laboratory under the supervision of a trained teacher or qualified scientist. Examples include cloning of DNA in Es c h er i c hi a c ol i K-12, S a c c h ar o my c e s c e r ev i s i a e , and B a c i l l us s u bti l i s host-vector systems, students must be properly trained in standard microbiological practices before starting work.
b.
Work involving host-vector systems with as vectors may be conducted in a plasmids under the supervision of a trained teacher or qualified scientist.
c.
Biological expression systems are vectors and host cells that fulfil a number of criteria that make them safe to use. A good example of a biological expression system suitable for use in schools is plasmid pUC18 (or derivatives thereof), which is c ol i frequently used as a cloning vector in combination with E. K-12 cells. The pUC18 plasmid and its derivatives have been entirely sequenced. More importantly, all genes required for efficient transfer to other bacteria have been deleted from the precursor plasmid pBR322 providing significant containment, c ol i K-12 is a strain that is, the plasmid is non-conjugative. E. E. coli strains that lacks the genes known to render some E. c ol i K-12 cannot permanently pathogenic. Furthermore, colonise the gut of healthy humans or animals. Thus, most routine genetic engineering experiments can be performed E. coli K-12/pUC18 at BSL-1 provided the inserted safely in foreign DNA sequences do not require a higher BSL.
~ 237-
nonnon-conjugative BSL-1 laboratory,