LONG-TERM STABILITY OF BACULOVIRUSES STORED UNDER VARIOUS CONDITIONS

The long-term stability of baculoviruses under various storage conditi ons was investigated. The results showed that the titers of baculoviru s working stocks were significantly reduced after the viruses had been stored in polypropylene tubes for several months or a year at 4 degre es C. The virus was not lost by sticking to the plastic tubes, because the same results were obtained when the virus was stored in glass tub es. The major factor contributing to the loss of viral infectivity was exposure to light. Virus stocks stored at temperatures ranging from - 85 degrees to 37 degrees C were quite stable, as long as they were pro tected from light. Finally, viral infectivity was not significantly re duced by multiple freeze-thaw cycles. These results demonstrated that baculovirus working stocks may be stored frozen or refrigerated with l ittle long-term loss of infectivity, as long as they are protected fro m light.