Free viral DNA present in BKV hamster osteosarcoma (Os-513) cell clones

We analyzed 10 clones from cell line Os-513, which has originated from a BK virus-induced hamster osteosarcoma and contains only free defective viral DNA, for viral DNA by electrophoresis followed by blot hybridization. Like the parental line, all the clones contained both monomeric and polymeric viral DNA. The quantities of viral DNA per cell differed among the clones and the subclones. The results suggest that, although the number of copies of viral genomes per cell is variable, the basic forms of free viral DNA in the transformed cells are stably inherited by the progeny cells during cell growth.