COS-7 nuclear extract
Active Motif's COS-7 nuclear extract was prepared from subconfluent undifferentiated cell cultures of the Simian kidney fibroblast COS-7 cell line. The COS-7 cell line was derived from immortalizing the African green monkey CV-1 cell line by transformation with an origin-defective mutant of the SV40 viral genome that is replication-deficient but produces wild-type large T antigen. The large T antigen supports replication and lytic growth of the SV40 virus as well as replication of SV40 promoter-containing plasmids. In addition to supporting propagation of the Simian SV40 virus, the COS-7 cell line is most commonly used in research related to replication and in transfection studies for the production of recombinant proteins.