In vitro replication of duplex circular DNA containing the simian virus 40 DNA origin site

Extracts (0.2 M NaCl) of HeLa cells support replication of DNA containing simian virus 40 (SV40) origin in the presence of SV40 large tumor (T) antigen. The reaction leads to the accumulation of high molecular weight products that represent DNA containing one parental strand and one progeny strand as well as duplex molecules that contain both strands derived from the input deoxynucleoside triphosphates. The replication reaction is inhibited by aphidicolin and by camptothecin, two inhibitors known to inhibit eukaryotic DNA replication in vivo.