Immortalization of human fibroblasts by liposome-mediated transfer of SV40 early region genes

Transfer of simian virus 40 (SV40) early region genes into normal cells is one of the most useful methods of obtaining immortalized cell lines. The SV40 early region encodes viral proteins that cause an increased, but finite, cellular proliferative potential; immortalization requires additional genetic changes. The following protocol describes plasmid-mediated transfer of SV40 early region genes into human fibroblasts and cell culture conditions designed to maximize the probability of obtaining an immortalized cell line. This approach may be used for any cell type.