Due to the outbreak of the new coronavirus, the construction of PCR gene amplification laboratories in various places has gradually accelerated. Viral nucleic acid detection is an important standard for the diagnosis of new coronary pneumonia. PCR laboratory, also known as gene amplification laboratory, adopts molecular biology technology. By amplifying nucleic acid fragments, it can also be regarded as a special nucleic acid replication in vitro. The gene tracking system is used to grasp the virus content in the human body, and the detection accuracy can reach the nanometer level. New coronavirus nucleic acid detection also belongs to this category of technology and is an important standard for the diagnosis of new coronary pneumonia.
The PCR gene amplification laboratory mainly amplifies the detection nucleic acid template. It can be seen that cross-contamination is most likely to occur in the laboratory, resulting in false positive results in test specimens. Therefore, PCR laboratories have strict design requirements and standards.
Now PCR technology has been widely used in the fields of infectious diseases, tumor targeting, reproductive genetics, etc. However, due to the multiple and large amplification of the nucleic acid to be tested by this technology, even a very small amount of contamination can easily lead to second, PCR The technical requirements are relatively high, and the experimental process is complicated. If there are omissions in the intermediate links, false negative results may be caused.
1. It is the contamination of PCR amplification products. It is also the most common cause of contamination. After repeated amplification of PCR products, the amount of replication far exceeds the detection limit of PCR, so even a very small amount of contamination is enough to cause false positives in experimental results.
2. Reagent contamination. During reagent preparation, contact with contaminated containers, pipettes, pipette tips, solutions, etc., can lead to contamination of reagents.
3. The sample to be tested is contaminated. The container in which the sample is placed is contaminated or the sample is contaminated due to the poor sealing of the container; secondly, the use of contaminated pipettes or pipette tips during the nucleic acid extraction process will lead to contamination of the sample; in addition, some samples contain viruses, If diffused into the air, cross-contamination may occur.
4. Aerosol pollution. If the aerosol contains viruses and other pollutants and spreads into the air, it is very likely to cause PCR product contamination. Aerosols are created by friction between air and the surface of a liquid. Opening the lid, shaking the reaction tube, and repeatedly aspirating the contamination sampler can form aerosols that can lead to cross-contamination. After calculation, one aerosol particle can contain 48,000 parts, so special attention should be paid to the pollution caused by aerosol. As long as the PCR laboratory is contaminated, the previous result report is invalid and other experimental operations cannot be performed. The source of contamination must be identified and thoroughly removed in order to obtain accurate and effective experimental results.
