Are you asking about spraying 75% alcohol on the outer layer of the large sample bag after it is sealed? After the large sample bag is sealed, the outer layer should be sprayed with 75% alcohol. 75% alcohol has a disinfecting effect. In the process of collecting, sending and processing COVID-19 nucleic acid test specimens, it is stipulated that after the large sample bag is sealed, 75% alcohol needs to be sprayed on the outer layer for disinfection. Therefore, after the large sample bag is sealed, 75% alcohol must be sprayed on the outer layer.