pASK-IBA6C is a classic cloning vector devised for E. coli expression of recombinant proteins with the Strep-tag®II fused to the N-terminus. It carries the chloramphenicol resistance cassette for selection of transformed E. coli cells, F1 and ColE1 origin for a high plasmid copy number, a multiple cloning site with recognition sites for several common restriction enzymes (e.g. EcoRI, SmaI, BamHI, SalI, PstI), the inducible tetracycline promoter/operator for the regulated expression of proteins, the ompA signal for periplasmic secretion of the recombinant protein, and the sequence for a protease cleavage site. The vector can be combined with any E. coli strain since the tet-promoter works independently of the genetic background of E. coli. Expression of the recombinant protein is induced by addition of anhydrotetracycline, which is a derivative of tetracycline that does not exhibit antibiotic activity. During the secretion into the periplasmic space the ompA signal sequence will be cleaved off. The N-terminal Strep-tag®II can be removed by the protease factor Xa.