Antigen test kits generally refer to novel coronavirus antigen test kits, where two bars are positive, one bar is negative, and no bar is an invalid result. The Novel Coronavirus Antigen Test Kit is a self-test for Novel Coronavirus Pneumonia that can be used to screen specific populations, but is not a complete replacement for nucleic acid testing. Normally, after using the Novel Coronavirus Antigen Test Kit, if there are two bars in the C position and T position, the result is positive, indicating that the patient may be infected with the Novel Coronavirus. If there is one bar in the C position but no bar in the T position, the result is negative, indicating that the organism is not infected with the novel coronavirus. It is worth noting that if there is no bar in the C and T positions, the result is invalid, probably due to improper operation, and the novel coronavirus antigen test kit needs to be re-tested. If you are suspected to have symptoms of novel coronavirus pneumonia but the novel coronavirus antigen test kit is negative, you should still seek medical attention as soon as possible for nucleic acid testing to clarify whether you are infected with novel coronavirus. It is recommended that people follow the instructions strictly to ensure the accuracy of the test results. Tip: “New coronavirus pneumonia” and “new coronavirus pneumonia” mentioned in this article have been renamed to “new coronavirus infection” on December 26, 2022, as announced by the National Health Commission.