Plasmid pCMV·SPORT-bgal was used as a
positive control for monitoring expression in eukaryotic cells. This plasmid contains the reporter gene β-galactosidase (β-gal) from E. coli, which was cloned into the plasmid pCMV·SPORT1 as a non-I fragment particle. This plasmid also contains the
CMV promoter upstream of the β-gal gene, as well as the SV40
t-intron and polyadenylation signal. The beta-lactamase gene enables ampicillin resistance screening in
E. coli.