| Abstract: | SV40 was photodynamically inactivated in the presence of Toluidine blue 0 by irradiation with white light for different periods of time. Different functions of SV40 were inactivated at different rates. The most sensitive function was the capacity of the virus to replicate followed by the capacity to induce T antigen and cell DNA synthesis. The transformation capacity was the most resistant. No evidence was obtained that the survival of transformation activity after large decrease in infectivity was due to multiplicity reactivation. Syrian hamster kidney cells transformed in vitro by photodynamically inactivated SV40 had the same properties as those transformed by control virus. They showed identical morphology, were T-antigen positive, contained the same number of SV40 DNA genome equivalents integrated in their DNA and were oncogenic when inoculated into adult hamsters. |
