STABILITY OF HEPATITIS A VIRUS TO PHYSICOCHEMICAL AGENTS
The stability and inactivatio of HAV strain FM-175 was studied in tissue culture with quantitative radioimmunofocus (RIF) assay. The virus used in this test was prepared from infected BSC-1 cells freezed and thawed 3 times and centrifuged at 3000rpm. The infectivity of HAV strain FM-175 was stable at pH 2.0-10.0, inactivated by 50% (log titer) by heating at 60℃ for 10 minutes, but some infectivity after heating at this temperature for 4 hours. HAV infectivity was significantly preserved by the presence of 2M MgCl2, 2M MgSO4 or 2M CaCl2. This virus did not resist lyophilization. It was rapidly inactivated by UV light irradiation, 3-8% formaldehyde, 2% phenol, 400ppm available chlorine and 70% ethanol.