The cells ar5e SV40 transformed and are positive for SV40 T-antigen; About 2% of the cells are positive for SV40 viral antigen, but virus is not recoverable; Tested and found negative for ectromelia virus (mousepox)Tumorigenecity: noIsoenzyme: Histopathology: normalSubculture: Split ratio: Media change: Reverse transcritase: negativeProduction.