BL21 (DE3) Competent Cells
Chemically Competent Escherichia coli Cells optimized for Protein Expression of T7 RNA Polymerase-based systems
BL21 (DE3) Competent Cells are Chemically Competent Escherichia coli Cells used for Protein Expression of T7 RNA Polymerase-based Systems. These cells are resistant to the lytic bacteriophages T1 and T5. The BL21 (DE3) strain is a derivative of E. coli B. It is deficient in both lon and ompT proteases resulting in superior isolation of intact Recombinant Proteins. The host is a lysogen of DE3 and, therefore, carries a chromosomal copy of the T7 RNA polymerase gene that is controlled by the lacUV5 promoter. The strain utilizes the T7 RNA promoter to control protein expression. IPTG is used to induce Expression of the T7 RNA Polymerase.
Genotype: F¯ ompT gal dcm lon hsdSB(rB- mB-) λ(DE3 *lacI lacUV5-T7 gene 1 ind1 sam7 nin5])