In the whole anti-epidemic process, nucleic acid testing can catch the virus in time, so that it has no place to hide, and is a real "anti-epidemic hero". So, what is the secret of nucleic acid testing to become a "virus hunter"?

Nucleic acids are not acids!

Nucleic acid, although it sounds like an acid, it is not an acid. It is a substance that we share with animals, plants, viruses and all life in general, so it can be used to track and detect viruses.

So it is why they call nucleic acid our problematic name? It depends on the story of how it was discovered. In 1869, Michel was isolating this social substance, which Michel called nucleoprotein, from the pus of a traditional surgical bandage.Rapid antigen nasal swab However after nucleoprotein was discovered on its own, it didn't can be taken seriously by Chinese scientists.

An instant later, in 1879, Michel's youngest son, a biologist named Cossell, noticed the little creature. Until now, the nature of nucleoproteins was unknown. kosel looked closely at nucleoproteins and realized that they also contained an acid called nucleic acid. in 1910, he was awarded the Nobel Prize in Physiology or Medicine for his work on nucleic acids.

We now know that there are two types of nucleic acids. One is deoxyribonucleic acid, which has another famous name - DNA. the other is ribonucleic acid, or RNA. the discovery and study of nucleic acids is one of the great events of modern science, the genetic code of life. the discovery and study of nucleic acids is one of the great events of modern science, the genetic code of life. Thirty-eight scientists have won Nobel Prizes for their work on nucleic acids! For example, in 1953, Watson of the United States and Crick of the United Kingdom proposed a molecular model of the double-helix structure of DNA, which was hailed as one of the most important scientific discoveries of the 20th century. They also won the Nobel Prize in Medicine in 1962.

Unlike DNA, RNA has only one strand. We humans have both DNA and RNA. viruses, unlike us, usually have only one nucleic acid.

Each organism's nucleic acid is unique. After the emergence of the new coronavirus, Chinese scientists finished analyzing the whole genome sequence of the new coronavirus in a very short time. It was found to have a very simple structure, with a protein shell on the outside and a specific ribonucleic acid sequence (RNA) inside, which is the genetic material of the virus. In other words, as long as you find this string of different nucleic acid sequences, it's like getting the fingerprints of a suspect and catching the virus.

Hunting Knife - Polymerase Chain Reaction

With the virus "fingerprint" is not enough, but also have a "fast knife" to be able to arrest it, this "fast knife" is through the polymerase enzyme and chain reaction, also known as the PCR technology.

Pneumonia is hidden in the human body. Medical personnel take secretions from your upper respiratory tract with a nasal or throat swab and analyze the secretions to see if the virus is present. But the secretions are mixed, including your nucleic acid sequence and the nucleic acid sequence of the virus. How can you find the exact nucleic acid sequence of the virus? This is when PCR technology comes into play.

PCR is a method invented by Muhlis in 1985. It is a molecular biology technique for amplifying specific nucleic acid sequences, which can greatly increase the amount of viral nucleic acid secreted and open the door to modern life science research. Because of this, Mullis won the 1993 Nobel Prize in Chemistry.

When we get viral RNA, PCR translates it into readable cDNA, and in order to see the virus in real time, we release a "signaling bomb" - fluorescence. When the number of nucleic acid sequences specific to C. neoformans increases, the fluorescence intensity increases, which means that the patient is infected with the virus and the result is positive, otherwise it is negative. That is why this technique is also known as quantitative fluorescent PCR.

Is nucleic acid testing reliable?

The outbreak of nucleic acid testing is often characterized by "false negatives" and "false positives", but in reality, this is not due to the technology of nucleic acid testing, but rather to other factors.

If the amount of virus in the collected secretions is very small, or if the sample is collected incorrectly, the amount of viral RNA in the sample is too small for PCR to replicate.

The immaturity of the detection reagents, in the early stages of the epidemic, the knowledge of the nucleic acid sequence of the virus itself was still imperfect, especially for the virus itself which is still evolving new types in China. Usually as a reagent kit needs to go through a number of important steps such as research and development, production, approval and so on to realize the real can be applied to patients, this work time for 3~5 years. And the epidemic can not withstand such a long time, when the nucleic acid test kits may result in the inability to detect all data types of viruses. At the same time, the nucleic acid testing system operation process steps are complex, the operator's requirements have a high, improper operation and management can also cause false impressions.