The ZAP Express and the Lambda ZAP-CMV vectors combine the high efficiency of lambda vector systems with the versatility of plasmid systems.

The ZAP Express vectors enable both prokaryotic and eukaryotic expression of gene of interest.

In vivo excision of the ZAP Express vector yields the PBK-CMV vector.

The Lambda ZAP-CMV vector enables high-level eukaryotic expression of gene of interest. In vivo excision of the lambda ZAP-CMV vector yields the pCMV-Script-EX vector.

The CMV immediate early promoter drives gene expression in mammalian cells.

The lacZ promoter drives prokaryotic expression, while the CMV immediate early promoter drives gene expression in mammalian cells.