Application of High Frequency Piezo Micro‐ vibration Control in Digital PCR Technology At the end of the 20th century, Vogelstein et al. proposed the concept of digital PCR (digital PCR, dPCR), by dividing a sample into tens to tens of thousands of copies and assigning them to different reaction units, each unit contains at least one copy of the target molecule (DNA template). In each reaction unit, the target molecule is amplified by PCR, and after the amplification is completed, the fluorescent signal of each reaction unit is statistically analyzed. Digital PCR is an absolute quantification technology of nucleic acid molecules, which mainly adopts microfluidic or dropletization methods in the current popular research field of analytical chemistry. Digital PCR generally includes two parts, namely PCR amplification and fluorescence quantitative analysis. In the PCR amplification stage, unlike traditional techniques, dPCR generally requires the sample to be diluted to a single molecule level and distributed evenly to tens of thousands of reaction chambers. This is equivalent to enriching the target gene in disguised form. At the same time, due to the large dilution of the original sample, the concentration of PCR inhibitors was significantly reduced, so that the requirements of dPCR for the inhibitors in the initial PCR reaction were significantly lower than that of qPCR (Quantitative Real‐time PCR). Different from the method of qPCR for real‐time fluorescence measurement of each cycle, dPCR technology collects the fluorescence signal of each reaction unit after the amplification is completed. The droplet with fluorescent signal is interpreted as 1, and the droplet without fluorescent signal is interpreted as 0, and finally the initial copy number or concentration of the target molecule is obtained according to the principle of Poisson distribution and the number and proportion of positive droplets.
Basic Principles of Picture Digital PCR Based on the different methods of liquid separation, digital PCR is mainly divided into three types:
Microfluidic digital PCR (mdPCR), droplet digital PCR (ddPCR), chip digital PCR (Chip digital PCR, cdPCR), The liquid separation is achieved through microfluidic channels, microdroplets or microfluidic chips. Each small area separated can be subjected to a separate PCR reaction. Among them, mdPCR is based on microfluidic technology to separate the DNA template. The control technology can realize the sample nano‐upgrade or the generation of smaller droplets, but the droplets need a special adsorption method and then combined with the PCR reaction system. mdPCR has gradually been replaced by other methods; ddPCR technology is a relatively mature digital PCR platform, which uses oil water droplet generation technology generates 20,000 nanoscale droplets from the reaction system containing nucleic acid molecules. After PCR amplification, the droplet analyzer detects each droplet one by one; cdPCR uses microfluidic chip technology to integrate sample preparation, reaction, separation and detection on a chip,using integrated fluid pathway technology to engrave many microtubes and microcavities on silicon wafers or quartz glass, and control the flow of solutions through different control valves to realize the separation, mixing, and PCR amplification of biological samples to achieve absolute quantification . CoreMorrow's piezo ceramic actuators are suitable for all kinds of micro‐operation and micro‐ control applications with their excellent performance and convenient operation. CoreMorrow's piezo ceramic actuator adopts piezo vibration technology, which can generate high‐precision, high‐ frequency and controllable micro‐vibration, which is very suitable for micro‐fluid control or material dispersion in PCR equipment. CoreMorrow's Piezo Ceramic Actuator CoreMorrow's piezo ceramic actuator has many types, such as small size, high frequency, high output, low temperature vacuum, etc. The specific choice depends on the working parameters and structure of the user's equipment. Piezo Ceramic Stack
CoreMorrow has hundreds of piezo ceramic stack models, with diversified sizes and parameters, and the deformation and displacement generated from 1‰ to 2‰, and the no‐load resonance frequency is very high, reaching nearly 500kHz. In addition, the size of the piezo ceramic stack is
very small. The common cross‐sectional dimensions are 2×2mm, 3.5×3.5mm, 5×5mm, 7×7mm, 10×10mm, etc. Even with such a small cross‐section, the output force can reach thousands of Newtons. Piezo ceramic stacks are generally fixed and installed by glue bonding. Piezo Actuator
Piezo ceramic actuators are very suitable as vibration excitation sources, and the working frequency can reach kilohertz. Compared with piezo ceramic stacks, CoreMorrow's piezo ceramic actuator has a metal protective shell on the outside, which has higher reliability and can withstand a certain pulling force. In addition, the torsion‐resistant piezo ceramic actuator has a certain torsion resistance function, which can prevent the internal piezo ceramics from being damaged by torsion during the installation process. The mobile end of the piezo ceramic actuator has a variety of installation options, including flat head, ball head, external thread, internal thread or customized interface, and the installation method is very flexible and convenient. The longer the length of the piezo ceramic actuator, the greater its displacement range; the larger the diameter, the greater the output. It has two shapes: ring shape and column shape. In use, it can be installed upright, inverted or horizontally, but it is necessary to provide specific load and other parameters, and our technicians will analyze the feasibility and safety. Piezo Nanopositioning Stage
Compared with piezo ceramic actuators, CoreMorrow's piezo nano positioning stage can carry out multi‐directional (multi‐dimensional) motion control, and can freely select the direction of
movement and range of travel in 1 to 6 dimensions. Piezo nanopositioning stage generally adopts mechanical amplification structure, its stroke can be as long as 1mm, and the shape structure can be customized. The central through hole design can be selected, which is more suitable for sample installation. The working frequency of the piezo nanopositioning stage after loading is generally about several tens of Hz. Piezo Objective Lens Positioner/ Piezo objective Scanners
CoreMorrow's piezo objective lens positioner is specially designed for driving the objective lens. It can carry the objective lens for single‐axis focusing and positioning, with an accuracy of 2.5nm, which is very suitable for high‐precision microscopic imaging and other applications. The piezo objective lens positioner is connected with the objective lens through an adapter, which can quickly lock the objective lens in the desired position. A variety of threads are available, such as M27×0.75, M26×0.75, M26×1/36", M25×0.75, W0.8×1/36", etc. They can also be customized to facilitate integrated installation with the microscope. Piezo Tip Tilt Stage
CoreMorrow’s piezo tip tilt stage is a piezo platform that can perform angular motion, generally θx, θy two‐dimensional deflection, and θx, θy, θz and XYZ six‐axis motion can also be selected, and the movement adjustment is more flexible. The piezo tip tilt stage is suitable for sample leveling in microscopic imaging, and also suitable for optical path adjustment in imaging. The adjustment speed can reach the order of milliseconds, and the deflection accuracy can reach nanoradians. In addition to the above, CoreMorrow also have a variety of piezo motion control products, with a stroke of up to tens of millimeters. There are also more about medical application solutions, welcome to inquire us.