Escherichia coli B BL21 and its derivatives has been used for a long time for bacterial protein expression. Until now, they were commercially available at commercial prices. From now on, three E. coli BL21 strains are available via BCCM/GeneCorner at non-profit prices!
Escherichia coli B BL21(DE3) (LMBP 1455) is a production strain for IPTG induced T7 driven protein expression.
Escherichia coli B BL21(DE3)[pLysS] (LMBP 2462) contains the pLysS helper plasmid which reduces background T7-driven protein expression in the absene of IPTG.
Escherichia coli B BL21(DE3)[pLysE] (LMBP 2468) contains the pLysE helper plasmid which removes background T7-driven protein expression in the absene of IPTG, making this an ideal expression strain for toxic proteins.