Doing nucleic acid refers to the nucleic acid test of the new coronavirus. Doing nucleic acid every day is related to the fast mutation speed of the virus, the higher number of asymptomatic people, the incubation period of the disease and the error of the experimental results. 1. The virus mutates quickly: the new coronavirus mutates quickly, the mutated virus is more infectious and spreads quickly, requiring frequent nucleic acid to detect as many infected people as possible to control the spread of the epidemic. 2. More asymptomatic people: At present, most of the new crown patients are asymptomatic infected people, and have no obvious symptoms, so we need to do nucleic acid regularly to make clear whether they are sick or not, to reduce the spread of the epidemic. 3. Incubation period of the disease: the virus has an incubation period, so by increasing the number of nucleic acids can detect more hidden infected people. 4. Experimental result error: In the process of nucleic acid testing, problems such as unqualified sampling, long storage time, and test operation errors may cause result errors, so multiple tests are needed to reduce random errors and prevent misdiagnosis.