The validity of the nucleic acid test is calculated from the time the test results are available, and the validity may vary depending on the type of nucleic acid test and the requirements of epidemic prevention and control. Nucleic acid tests are mainly divided into nucleic acid tests for new coronary pneumonia, HPV and other nucleic acid tests such as HIV and hepatitis B. Nucleic acid tests for new coronary pneumonia are more commonly used and are subject to the requirements of epidemic prevention and control, so you should consult your local official agency for the specific expiration date. The validity period of the nucleic acid test should not be too long. In this regard, the health department as well as the CDC set the validity period for the Nucleic Acid Test for New Coronary Pneumonia according to the epidemic situation at different times and in different areas, which is commonly 24 hours, 3 days or 7 days. However, if there is a wide range of activities or contact with suspected patients within a short period of time, even within the validity period, you should immediately redo the nucleic acid test again; 2. HPV nucleic acid test: HPV nucleic acid test generally does not have a validity period. If it is high-risk, it is recommended to check every six months after the cure is more secure; 3, other nucleic acid testing: such as HIV nucleic acid testing, hepatitis B nucleic acid testing and other general does not exist in the validity of the statement. If the test result is negative, the second test can be conducted at a later time according to your own situation. If the test result is positive again after the next high-risk exposure, the treatment should be targeted according to the condition.