DiscoverX cloning vector bundles contain 2 or more pCMV Mammalian cloning vectors. The vectors are intended for cloning your protein of interest with the enhanced ProLabel® (ePL) or ProLink™ (PK) β-galactosidase small enzyme donor as a N- or C-terminal tag, and subsequently transfecting into a parental cell line for the ultimate generation of an enzyme complementation assay.