Beijing completes 1 million person times of nucLEIc acid detection of new coronavirus in one day, which no city can do in world nearly.

Nucleic acid detection itself is not complicated. We can summarize it as follows:

The substance of nucleic acid detection is the nucleic acid of virus. Nucleic acid detection is to find out whether there is foreign virus nucleic acid in respiratory tract samples, blood or feces of patients to determine whether they are infected by new coronavirus. Therefore, once the detection of nucleic acid "positive", it can prove that there is a virus in the patient's body.

After the new coronavirus infects the human body, it will first reproduce in the respiratory system, so we can determine whether the human body is infected with the virus by detecting the viral nucleic acid in sputum and nasopharyngeal swab. Therefore, novel coronavirus positive test can be used as a diagnostic standard for new coronavirus infection.

What is the principle of nucleic acid detection?

All organisms except novel coronavirus contain nucleic acids, nucleic acids including DNA and RNA. The new coronavirus is a virus that contains only RNA. The specific RNA sequence of the virus is a marker for distinguishing the virus from other pathogens. Novel coronavirus appeared China scientists completed novel coronavirus novel coronavirus in a very short time, and compared with other species genome sequences, we found the new nucleic acid sequence of coronavirus. If novel coronavirus novel coronavirus sequences were detected in the patients' laboratory, it was indicated that the patient might be infected by the new coronavirus.

What's novel coronavirus nucleic acid detection principle?

The technology of nucleic acid detection is open all over the world.

gmtlight novel coronavirus specific sequence is most frequently detected by fluorescent quantitative PCR (polymerase chain reaction), according to relevant professionals. The novel coronavirus nucleic acid (RNA) should be RT DNA before the PCR reaction, because the PCR reaction template is only DNA. In the PCR reaction system, a pair of specific primers and a TaqMan probe were included. The probe was a specific oligonucleotide sequence, and the two ends were labeled with reporter fluorescent group and quenched fluorescent group respectively. When the probe is complete, the fluorescence signal emitted by the reporter group is absorbed by the quenching group; if there is a target sequence in the reaction system, the probe is combined with the template in PCR reaction, the DNA polymerase digests the probe along the template by using the exonuclease activity of the enzyme, and the reporter group is separated from the quenching group to emit fluorescence. Every time a DNA strand is amplified, a fluorescent molecule is produced. The fluorescence quantitative PCR instrument can monitor that the number of cycles (CT value) of fluorescence reaching the preset threshold is related to the concentration of viral nucleic acid. The higher the concentration of viral nucleic acid is, the smaller the CT value is. The products of different manufacturers will determine the positive judgment value of the product according to the performance of their own products

How about the process of novel coronavirus nucleic acid detection process?

The novel coronavirus nucleic acid detection, first, according to the sample specification, "part of the sample collection, routine sample types include throat swabs, nasal swabs, sputum, bronchoalveolar lavage fluid, bronchoalveolar lavage fluid."

After obtaining the patient's samples, it is necessary to carry out the test as soon as possible. If the samples that need to be transported cannot be tested immediately, they should be packaged at low temperature according to the requirements of the instructions and sent to a special testing agency for testing. After receiving the sample, the testing institution shall extract the nucleic acid from the sample. The nucleic acid extraction reagent shall use the nucleic acid extraction kit specified in the approved product manual.

Viral RNA needs to be reverse transcripted into cDNA before amplification. The novel coronavirus should be used in PCR amplification and detection by using the fluorescent quantitative PCR instrument specified in the product specification and the Ct value obtained by fluorescence quantitative PCR.

Why can China organize large-scale nucleic acid testing activities?

The reasons are as follows:

1. China has a large number of volunteers to actively participate, many college students have carried out relevant training, ready to put into the front line;

2. China has a strong community service team, civil servants and soldiers

3. China has established perfect standards for nucleic acid detection and detailed division of labor; each step is a simple work.

4. Mature detection technology is the basic guarantee;

In fact, if necessary, China can organize more large-scale nucleic acid testing activities.