Viral nucleic acid detection VS antibody detection

Release time:

2020-09-02


According to the detection targets, the common clinical detection techniques for pathogens mainly include four categories: nucleic acid detection, antibody detection, antigen detection and culture method. The culture method has a long cycle and is beyond the scope of this article. Nucleic acid (DNA or RNA) is the genetic material of the virus. The pathogen can be determined by detecting its characteristic sequence; the human immune system can produce antibodies (IgG and IgG and IgM), by detecting the IgG or/and IgM in the patient's serum sample, the pathogen can be determined. Existing and developing rapid detection reagents for new coronaviruses also belong to these three categories.

Nucleic acid detection: The infectious disease of the new coronavirus is very strong. When sampling, staff often cannot get too close to the person being sampled. This can easily cause the problem of insufficient collection depth and unable to collect the samples that are really needed. Mr. Wang of Desheng Technology told the health community that the samples must be inactivated immediately after collection to reduce their potential infectivity. However, due to different inactivation techniques, the gene fragments of the virus after inactivation are likely to be degraded and are also included in the specimens. The virus cannot be detected. The inactivated virus Transport Medium currently developed by Desheng Technology is simple to operate and does not require liquid preparation. The system contains a high-efficiency virus lysis solution. The virus is inactivated immediately after sampling, which effectively prevents the risk of secondary infection. It contains nucleic acid Rnase enzyme. Inhibitors, to a greater degree, protect the virus nucleic acid from being stable and not degraded, greatly improving the efficiency of nucleic acid extraction.

 

Antibody detection: Based on the immunological principle of the specific combination of antigen and antibody, it is a traditional clinical pathogen detection method to detect the specific antibody corresponding to the pathogen in the patient's serum. The main methods include colloidal gold method, immunofluorescence chromatography, enzyme-linked immunoassay, Chemiluminescence method, etc. The colloidal gold method is convenient to operate, and the detection can be completed in 10-15 minutes; the immunofluorescence chromatography method requires instrument interpretation; the enzyme-linked immunoassay can be interpreted by a conventional microplate reader, with high sensitivity and many operating steps, and the detection time takes 1.5 hours ; The sensitivity of chemiluminescence method is also high, using automatic chemiluminescence immunoassay instrument, the detection time is generally about half an hour.

Generally speaking, compared with nucleic acid detection methods, antibody detection methods are simpler, sample source and processing are single, and easier to control. The operability and detection time of the antibody detection method is worse than the nucleic acid detection method, while the sensitivity and specificity are not as good as the nucleic acid detection method. In the actual detection process, the two must be combined detection, comprehensive judgment, and nucleic acid detection to ensure "good" , Antibody testing ensures "no leakage", increases the positive detection rate of virus carriers, and reduces the risk of transmission.