About ECOS 21 Competent Cells Strain: BL-21 (DE3)

This strain provides high level of protein expression. This strain carries the lambda DE3 lysogen, which expresses T7 RNA polymerase from the lacUV5 promoter by isopropyl-1-thio-ß-D-galactopyranoside (IPTG) induction. The mutated rne gene (rne131) encodes a truncated RNase E enzyme that lacks the ability to degrade mRNA, resulting in an increase in mRNA stability. BL-21 is deficient in lon protease and the outer membrane protease, OmpT. The lack of these proteases reduces degradation of heterologous proteins expressed in the strain. The transformation efficiency of BL-21 is usually low, so the 6 minute/ heat shock cold plating protocol” is recommended if high efficiency is desired.ECOS 21 Competent Cells are chemically competent and have been developed using a novel chemical preparation. ECOS technology makes the cell highly .