COVID-19 antigen test that can be self-checked at home is coming soon. What is the principle of testing reagents?

The State Council should carry out antigen testing for COVID-19 group according to the results of novel coronavirus disease detection. The plan clearly stipulates that if community residents have self-inspection needs, they can purchase antigen detection reagents for self-inspection through retail pharmacies, online sales platforms and other channels. Coronavirus pneumonia-19 has four main structural proteins: S protein (S protein), nucleocapsid protein (N protein), membrane protein (M protein) and envelope protein (E protein).

Once the human body is infected with the virus, these structural proteins can be used as immunogens to stimulate plasma cells to produce specific antibodies. The approved antigen detection products mainly use coronavirus pneumonia-19N protein as the target of antigen detection. The sample source of antigen detection is usually nasal cavity, throat or saliva. One of its characteristics is that it produces results quickly, which can be achieved in about 15 minutes. It can realize the early transfer of suspects. The operation is relatively simple, and the price is cheaper among the three detection methods, but the sensitivity of antigen detection is also low.

Nucleic acid detection is more accurate. Although there is no perfect detection method, nucleic acid detection is obviously closer to perfection than antigen detection. The data show that the accuracy of the commonly used antigen detection kit for asymptomatic infection is only 58%. Nucleic acid detection can know the number of viruses in this way, which is helpful to analyze the subsequent changes and control the epidemic as a whole. Antigen testing can only know whether there is infection. Data sharing is not easy to achieve. Nucleic acid detection is carried out in the organization, and the results are networked, which is convenient for inquiry and locking. Self-inspection and notification of antigens depend on self-awareness, which is not conducive to the traceability of the epidemic.

Nucleic acid detection is still the mainstream, with the ability of nucleic acid detection. Give out antigen test boxes for people to test themselves, so as to know whether the tester is infectious faster and isolate the most infectious patients as soon as possible. Antigen detection and nucleic acid detection should be complementary. Both nucleic acid and antigen are important detection methods, and each has its own most applicable occasions. For example, in the absence of nucleic acid detection ability, such as being far away from the detection point, or having fever or cold symptoms in the middle of the night, more convenient antigen detection can be used.