BL21 Competent E. coli
New England Biolabs Inc.BL21 Competent E. coli is a widely used non-T7 expression E. coli strain and is suitable for transformation and protein expression. This strain does not express the T7 RNA Polymerase. Ideal for Plac, Ptac, Ptrc ParaBAD expression vectors Protease deficient No dry ice surcharge on competent cell shipments Outgrowth medium included Free of animal products