Cannot be used. After the test tube comes into contact with cold air, the reagents in the tube will easily freeze. If frozen, the reagent in the tube will be invalid and will also affect the residents' testing work. Therefore, the nucleic acid sampler cannot be used if it is frozen. Samplers (swabs, swabs, etc.) Cotton swab) is a type of medical device product used for nucleic acid detection. It belongs to the lowest level category of low risk and easy to control.