PCR (polymerase chain reaction) is a method of molecular biology that allows you to achieve a significant increase in small concentrations of certain DNA fragments in a sample, as well as to perform some manipulations with DNA. In medical practice, PCR is often used to diagnose infectious and hereditary diseases, to clone and isolate new genes, and to establish paternity.
In simple terms, PCR is a multiple magnification of a certain section of DNA to obtain more accurate information within the framework of an ongoing study. PCR with very high accuracy detects viruses, fungi, bacteria and other types of foreign microbes in human biological materials (blood serum, urine, saliva and other body fluids that may contain a pathogen).
Biological samples submitted by a person are exposed to a chemical reagent that “highlights” fragments of the genome of the pathogen of the disease. After that, using amplification by the enzyme polymerase and exposure to weak electric currents, the fragments found are enlarged, which allows computer equipment to see them. Well, then, as they say, it’s a matter of technology.
PCR allows you to identify a virus, bacterium, fungus, etc. even with a very small content of it in the human body and in the absence of symptoms of the disease.
PCR allows you to understand whether a person is infected or not. And if so, with what. PCR does not allow you to determine how long ago the infection occurred, at what stage of the disease, etc.There are other tests and research methods for this.
Polymerase chain reaction (PCR) was invented not so long ago – in 1983. This was done by the American scientist Cary Mullis, who was later awarded the Nobel Prize for this invention.
It is worth noting that even today, PCR diagnostics is one of the most accurate and sensitive methods for diagnosing infectious diseases, including long-growing pathogens. For the determination of many infections, the PCR method has become the “gold standard”, as it is time-tested and allows you to determine the causative agent of the disease even if there are only a few DNA molecules of the pathogen in the sample received from the patient.
Alas, things are not so good with the new SARS-CoV-2 coronavirus, which causes the COVID-19 coronavirus infection. You can learn more about the PCR test for coronavirus here.