Plasmid pCMV·SPORT-bgal is used as a positive control for
monitoring expression in eukaryotic cells. The plasmid contains the
reporter gene b-galactosidase (b-gal) from E. coli cloned as a Not I
fragment into plasmid pCMV·SPORT1. The plasmid also contains
a CMV promoter upstream of the b-gal gene, followed by the SV40
t-intron and polyadenylation signal. The b-lactamase gene allows
selection for ampicillin resistance in E. coli.