Kinetics of inactivation of African swine fever antigen with binary ethylenimine
Proceedings of the United States Animal Health Association 86: 253-260
African swine fever (ASF) soluble antigen for routine diagnostic tests is produced from infected Vero cells. The residual infectivity of antigen after solubilization and ultracentrifugation ranges from 106.5 to 108.0ID50/ml. Antigen shipped from Plum Island Animal Disease Center has to be completely inactivated, while still retaining antigenicity. Since binary ethylenimine (BEI) inactivates nucleic acid with minimal effect on protein, it was used to inactivate the residual virus present in soluble ASF antigen. The effect of time, temperature and concentration of BEI was studied. Inactivation with 10 mM BEI at 37 degrees C for 3 hours completely inactivated the virus, but some loss of antigenic activity occurred. Inactivation with 10mM BEI for 20 hours at 17 degrees C assured complete loss of infectivity while still retaining most of the antigenic activity.