Antigen testing is a way to detect the presence of viral infections in the body, and the time required for testing varies for different viruses. For example, testing for novel coronavirus takes about 15 minutes to produce results, testing for influenza virus takes about 30 minutes to produce results, and antigen testing for most viruses will produce results within 1 day. Antigen testing has become an important complement to nucleic acid testing as a means of screening for novel coronavirus pneumonia. Primarily, the test involves testing the saliva of a suspected infected person by dipping the test strip into about 2 ml of fresh saliva for about 2 minutes and waiting another 15 minutes or so for the results to be available. This test is more convenient, faster and can shorten the detection time to a greater extent, which is more conducive to outbreak prevention and control. The antigen test is an important complement to the nucleic acid test, which mainly detects the antigenic shell of the virus and can be detected more easily because it does not touch the core genes of the virus and the testing procedure is simpler. Compared to nucleic acid testing, antigen testing is more convenient and faster, with rapid results in 15-20 minutes, but at the same time less accurate. Because of its convenience, antigen testing can be done continuously. According to clinical experience, it is recommended that antigen testing be performed for 5 consecutive days for suspected infected persons to improve the accuracy of test results to a greater extent. For people who need antigen testing, it is recommended to consult a professional doctor according to their own situation to clarify the type of test, and the specific time for the results to be shown on the test paper. If you are worried about the error of the test results, you can perform two antigen tests at the same time as a comparison, or perform more than 5 days of continuous testing to improve the accuracy of the test results.