File:Jr rmf 4.jpg

A Schematic representation of vector pET28a. Not that the vector has a constitutive LacI expression cassette. B BL21 DE3 cells holding the empty pET28a vector at 10mM IPTG. The vector is obviously nontoxic to cells even at high concentrations of inducer. C Decreased viability of BL21 DE3 cells harboring vector pET28a-RMF wild type at 1mM IPTG and 10mM IPTG.