QIAexpress pQE vectors and constructs can be maintained in any E. coli strain that is ampicillin-sensitive and carries the pREP4 repressor plasmid, or harbors the lacIq gene on the F-factor episome. Alternatively, thepQE-80L series of expression vectors which encodes a lacIq repression module, allows use of any E. coli host strain. 配套表達菌株為M15[pREP4].