New England Biolabs introduces a tunable T7 expression strain for challenging proteins

Ipswich, MA (January 5, 2010) – New England Biolabs (NEB) has introduced Lemo21(DE3) Competent E. coli, a tunable T7 expression strain optimized for the expression of difficult constructs, including membrane proteins, toxic proteins and proteins prone to insoluble expression. A derivative of BL21(DE3), Lemo21(DE3) offers the host features of this commonly used expression strain, with the added benefit of being able to finely tune T7 expression. Tunable expression is achieved by varying the T7 RNA Polymerase activity to determine the optimal level of expression for each individual target protein.

Lemo21(DE3) is the first commercial product from NEB based on the Lemo System™, a technology developed by Xbrane Bioscience, a company originating from the Center for Biomembrane Research at Stockholm University. NEB and Xbrane Bioscience recently announced an agreement in which NEB would commercialize products based on the Lemo System through its international distribution network. Additionally, the technology is available for licensing by both companies.

Lemo21(DE3) Competent E. coli is being launched at the Pep Talk 2010 Protein Expression Conference, January 12-15, 2010 in San Diego, CA.

For more information, visit