Rumor Identification: No, a negative nucleic acid test is not a basis for ruling out infection. Explanation of the rumor: 1. False negatives are a type of test error. In fact, false negatives can occur with all tests. There are several common possible and influential factors that can lead to this result: failure to collect the sample or collecting too few specimens; errors in storage, transportation, and testing processes; and the accuracy of the kit. 2. For patients who have not yet been diagnosed, they will be classified as suspected patients. Suspected patients will also undergo nucleic acid testing and differential diagnosis several times during the follow-up consultation and treatment process, and eventually get a confirmed diagnosis. Therefore, a negative nucleic acid test does not mean that the suspected infected person is left alone, and there is no need to worry about a large number of missed patients. Special Note: Nucleic acid testing can be performed in a variety of ways to extract samples, such as blood and throat swabs. In the case of novel coronavirus, for example, most use sputum retention, and lower respiratory secretions are collected from patients with tracheal intubation, and specimens are sent for testing as soon as possible after collection.