An improved method for isolating viruses from asymptomatic carrier fish

This paper describes a method using elevated levels of penicillin, streptomycin, and nystatin instead of filters to control bacteria and mold contaminants in specimens processed for virus isolation. Filters were shown to significantly reduce the virus concentration. Virus and tissue cultures were not affected by this procedure. In field tests nearly three times more specimens were positive for virus with this method than with the widely used filter technique. Moreover, the cost of materials was less. This method is recommended for inspection and certification purposes.