Virus detection knowledge points
1. Collect specimens: the new coronavirus is through the mural of the human body, so we have to call
Collect specimens through the suction duct. Wiping is with throat swab, nasal swab in the previous book (pharynx or nasal cavity)
Swab collection: The other is the collection of lower throat fluid, lavage fluid, and alveolar lavage fluid.
2. Peeling and peeling: The skin is wrapped around the outside.
destroyed. After we collect the specimens, we strip off the surface of the virus from the biological cell activation solution,
It is the "streaking" RNA.
3. Copy, copy and copy: After extracting the RNA fragment, use PCR (polymerase chain reverse
Should) method to copy that and that lens. Like we found a special "tag"
You can identify the most special piece of information about the new coronavirus, and then identify it after identifying it
After duplication, this kind of scene duplication reaches the tens of billions level, it is easy to find it.
4. Fluorescence "visualization": In order to find the viral nucleic acid more conveniently, we add
Insert a fluorescent probe for labeling, and then use the instrument to read the fluorescence intensity to obtain a fluorescence curve. At this time, the information of the new coronary pneumonia virus can be captured.
Pros and cons
Advantages: nucleic acid detection has the advantages of early, sensitive and high specificity. Genetic testing
The sensitivity is high because it has a gene amplification process, which can expand a gene sequence into multiple, which is convenient for the result judgment. This is the superiority of genetic testing. The specificity is that the gene amplification uses 2 unique genes of the new coronavirus. Sequence, as long as the gene sequence of the virus is detected, it means that it is infected.
Disadvantages: In the early stage of the onset of the patient, the amount of virus in the body is small, and it is difficult to detect; the location, amount, storage method and time of respiratory specimen collection will produce different results for the test. collection
The specimen is an open operation, which will bring a considerable risk of infection to the sampling doctor.
