E.coli BL21 (DE3)pLysS

F-ompT hsdSB (rB-, mB-) galdcmrne131 (DE3) pLysS (CamR). The p15a origin of pLysS makes this plasmid compatible with pUC or pBR322-derived plasmids. This strain also contains the DE3 lysogen that carries the T7 RNA polymerase gene under control of the lacUV5 promoter, and IPTG is required to induce expression of the T7 RNA polymerase.