Here from PCR laboratory layout, the main functions of the work area and equipment configuration, laboratory ventilation system and pressure control and other considerations to explain.
Gene amplification experiments, also known as PCR experiments, are characterized by the ability to increase the trace amount of DNA significantly, PCR is a routine method of molecular biology research and experiments, widely used in various fields of biology.
For example: AIDS testing, hepatitis B, avian disease, oncogene detection and diagnosis, DNA fingerprinting, individual identification, paternity testing and forensic evidence, animal and plant quarantine, animal and its derivatives testing, animal feed, cosmetics, food hygiene testing, genetically modified crops and genetically modified microorganisms testing.
PCR laboratory in principle for the reagent preparation area, sample preparation area, amplification area and amplification product analysis area of four separate work areas and has a dedicated corridor, the work area should be set up buffer room, the work area and the buffer room should be installed with a chain device.
The different functions of the work area should be separated and independent, the work area has a clear sign, can not be straight through, if closely linked to the need to install items transfer window. The first two zones are pre-amplification zones, the last two zones are post-amplification zones, pre-amplification zones and post-amplification zones should be strictly separated.
1, reagent preparation area: mainly for the preparation of reagents, packaging and the preparation of the main reaction mixture. Reagents and materials used for sample preparation should be directly transported to this area, not through other areas. Reagent raw materials must be stored in this area and prepared into the required reagents in this area. The main equipment in this area includes balances, refrigerators, centrifuges, sample fillers, and oscillators. There is no strict requirement for the control of airflow pressure in this zone.
2, sample preparation area: mainly for the preservation of samples, nucleic acid (RNA, DNA) extraction, storage and its addition to the amplification reaction tube and determination of DNA synthesis. The main equipment in this area includes refrigerator, biological safety cabinet, centrifuge, sample adding device, oscillator, constant temperature water bath and so on. The pressure gradient in this zone is required to be positive relative to neighboring zones to avoid aerosol contamination from neighboring zones into this zone.
3, amplification area: the function of this area is DNA amplification and determination of amplified fragments. In addition, the preparation of the reaction mixture (from the reagent storage and preparation area) into the reaction mixture and the addition of the prepared DNA template (from the specimen preparation area), etc. can also be carried out in this area. For control of airflow pressure, the pressure is negative with respect to neighboring zones to avoid leakage of aerosols from this zone.
To avoid contamination by aerosols, unnecessary movement within the area should be minimized. Individual operations such as sample addition should be performed in the ultra-clean bench. The equipment in this area consists of the Nucleic Acid Amplification Thermal Cycler, the Sampler, and the Ultra-Clean Table.
The power supply of the thermal cycler should be dedicated and equipped with a regulated power supply or UPS to prevent the impact of voltage fluctuations on the amplification assay mainly for DNA amplification. The pressure gradient in this zone is required to be negative relative to neighboring zones to avoid aerosol leakage from this zone.
4, amplification product analysis area: the determination of amplification products. The main equipment in this area are enzyme labeling instrument, plate washer, sample filler and water bath. The requirement of pressure gradient in this area is: negative pressure relative to the neighboring areas, in order to avoid diffusion of amplification products from this area to other areas.
There should be a unidirectional flow of experimental process, logistics, people and airflow between the areas, forming a unidirectional flow of protective barriers to avoid mutual interference between the experiments, to prevent the diffusion of aerosols to prevent contamination of the experimental process.
PCR laboratory does not have strict purification requirements, but in order to avoid the possibility of cross-contamination of the various experimental areas, it is appropriate to use the full delivery of the full exhaust airflow organization, strict control of the proportion of delivery and exhaust to ensure that the experimental area pressure requirements.
In addition, PCR laboratories usually have biological safety cabinets, fume hoods and other production equipment, this type of equipment and the use of large volume of exhaust air spacing, not with the air-conditioning system running time, which leads to these devices in the room when the equipment start and stop the room is very easy to lose pressure, the original normal pressure gradient is instantly destroyed. This is exactly where the difficulty lies in the design of the air conditioning system for PCR laboratories.
Laboratory enclosure should be solid, airtight. All yin and yang corners should be rounded transition, the inner wall is smooth, no dust accumulation, corrosion resistance, easy to clean and disinfect. Ground using PVC coil or epoxy resin self-running apron, the material should meet the requirements of no gaps, no leakage, smooth, corrosion-resistant.