The swabs used for nucleic acid sampling are dry swabs. The liquid contained in the sampling tube placed after sampling is the preservation liquid. It is divided into inactivation type preservation liquid and non-inactivation type preservation liquid. 1. Inactivating preservation solution is a virus lysis type preservation solution. The basic component is the modified nucleic acid extraction lysate. Its main components include guanidine salts and ribonuclease inhibitors. The inactivating type preservation solution can be stored at room temperature for a longer period of time, which reduces the cost of preserving and transporting virus samples. At the same time, the high concentration of guanidine salts can inactivate the virus, avoiding the operator to be infected when performing the test. 2. Non-inactivated preservation solution, which is a virus maintenance preservation solution. The base ingredient is the delivery medium as the base modified liquid. Its main components include Hanks base solution, antibiotics, bovine serum albumin BSA (V), biological buffers, cryoprotectants and amino acids. It must be strictly cryopreserved. Non-inactivated preservation solutions maintain viral activity in vitro, as well as antigenic and nucleic acid integrity. It can be used to culture and isolate viruses, as well as for antigen detection.