Taking the novel coronavirus antigen test as an example, the antigen test result is determined by the position and number of bars on the test card. If only one bar appears at C on the test card after the sample is dropped into the test card, the test result is negative, i.e. there is no presence of the new coronavirus in the body of the test taker; if a bar appears at both C and T, the test result is positive; if a bar does not appear at C, as C is a quality control area, it means that the antigen test is invalid and needs to be tested again. The new crown antigen test mainly detects viral surface proteins, which are not as accurate as nucleic acid tests, and is only used as a basis for identifying potential patients in advance, so the diagnosis of new crowns is still based on nucleic acid tests. If the antigen test is positive, it should be treated immediately to avoid delay.