The DES-Inducible/Secreted Kit provides the vector pMT/BiP/V5-His for inducible, secreted expression of recombinant proteins and a choice of Blasticidin (pCoBlast) or hygromycin (pCoHygro) selection. This vector offers the inducible metallothionein promoter that is induced upon addition of copper sulfate or cadmium chloride. The N-terminal signal sequence from 
the insect BiP gene is provided to direct the recombinant fusion protein through the secretory pathway of S2 cells into the culture medium. The pMT/BiP/V5-His vector offers the following additional features:

? Small size (3.6 kb) to improve DNA yields and increase subcloning efficiency
? C-terminal V5 epitope tag for rapid detection with Invitrogens Anti-V5 Antibody
? C-terminal 6xHis tag for simple purification of recombinant fusion proteins using nickel-chelating resin

To facilitate cloning, a set of three vectors-A, B, and C-is provided. Each vector has the multiple cloning site in a different reading frame relative to the BiP signal sequence.
pMT/BiP/V5-His is a 3.6 kb expression vector designed for use with the Drosophila Inducible/Secreted Expression System (DES?; Catalog nos. K4120-01 and K5120-01) available from Invitrogen. Upon transfection, the vector allows transient, inducible, secreted expression of your protein of interest in Drosophila cells. When cotransfected with the selection vector, 
pCoHygro or pCoBlast, included with the appropriate DES? Inducible/Secreted Kit, pMT/BiP/V5-His allows selection of stable cell lines exhibiting inducible, secreted expression of the protein of interest. The vector contains the following elements:
? The Drosophila metallothionein (MT) promoter for high-level, metal-inducible expression of the gene of interest in S2 cells (Angelichio et al., 1991; Bunch et al., 1988; Maroni et al., 1986; Olsen, 1992)
? Drosophila BiP secretion signal for secreted expression of the gene of interest (Kirkpatrick et al., 1995)
? Multiple cloning site to facilitate cloning the gene of interest
? C-terminal peptide containing the V5 epitope and polyhistidine (6xHis) tag for detection and purification of your protein of interest (if desired)
? Three reading frames to facilitate in-frame cloning with the C-terminal peptide
? Ampicillin resistance gene for selection of transformants in E. coli
The control plasmid, pMT/BiP/V5-His/GFP, is included for use as a positive control for transfection and expression.