pEF4/V5-His A, B, and C are 5.7 kb vectors derived from pEF1/V5-His and designed for overproduction of recombinant proteins in mammalian cell lines. Features of the vectors allow purification and detection of expressed proteins. High-level stable and transient expression can be carried out in most mammalian cells. The vectors contain thefollowing elements:

1. Human elongation factor 1a-subunit promoter (hEF-1α) promoter for high-level expression across a broad range of species and cell types (Goldman et al., 1996)(Mizushima and Nagata, 1990).
2. Three reading frames to facilitate in-frame cloning with a C-terminal tag encoding the V5 epitope and a polyhistidine metal-binding peptide.
3. Zeocin resistance gene for selection of stable cell lines (Mulsant et al., 1988).
4. Episomal replication in cell lines that are latently infected with SV40 or that express the SV40 large T antigen(e.g. COS7)

The control plasmid, pEF4/V5-His/lacZ is included for use as a positive control for transfection, expression, purification, and detection in the cell line of choice.