Antigen test and nucleic acid test have different detection substances and experimental principles. Antigen test and nucleic acid test are both used to detect whether the body carries a virus, antigen test mainly detects viral proteins, nucleic acid test mainly detects viral RNA. The principle of antigen detection is antigen-antibody reaction, the corresponding antigen of viral proteins will be immobilized on the carrier such as colloidal gold or latex, and if the sample contains viral proteins, these proteins will bind with the antibody on the carrier, which will make the test paper show color. Nucleic acid testing is more sensitive as the principle is to amplify the viral genetic material directly in the sample, usually using a fluorescent quantitative PCR method to amplify the sample. Both can be used to detect whether an organism is carrying a virus, with the nucleic acid test being more sensitive and specific than the antigen test, making it the gold standard for confirming a diagnosis.