Recently, several new crown antigen self-test products have been approved for marketing, which has attracted attention.   What is an antigen test, and what is the difference from the well-known nucleic acid test? Why add this new detection method? What is the detection accuracy? What does one need to do? Are there any risks? Doubts about this new form of detection emanate.   What exactly is an antigen test? How is it different from nucleic acid testing?   Antigens are like the “clothes” that the virus wears on the outside, and nucleic acids are the genes inside the virus.   These two tests are slightly different. The antigen test is a method that starts from the antibody to measure the “clothes”, and after the comprehensive specificity, the virus can be