HiPurA® BL21(DE3) Competent Cells

HiPurA® BL21(DE3) Competent Cells are specially prepared chemically competent BL21(DE3) cells which makes cloning experiments easier. Competent cells are ready-to-use bacterial cells that contain an altered cell membrane through which a foreign DNA can pass through very easily. HiPurA® BL21(DE3) Competent Cells are prepared by following a modified protocol of Hanahan (1983, J.Mol.Biol 166:557) and are recommended for regular sub cloning of recombinant plasmids. E.coli BL21(DE3) strain is a derivative of E.coli B Strain which lacks both the Ion protease & the ompT membrane protease which may degrade expressed proteins thus this strain is preferred for recombinant protein expression. BL21(DE3) contains ?DE3 Lysogen that has T7 RNA Polymerase gene under the control of lacUV5 promoter. This arrangement is on phage genome, called DE3. BL21(DE3) is suitable for expression from a T7 or T7 lac promoter or promoters recognized by the E.coli RNA polymerase such as lac, tac, trc, ParaBAD, PrhaBAD and also T5 promoter. IPTG is required for optimal expression of T7 RNA polymerase in order to express recombinant genes cloned downstream of T7 promoter. A stock of pUC19 Plasmid DNA is provided as a control to determine the transformation efficiency. To obtain maximum transformation efficiency, the experimental DNA must be free of phenol, ethanol, protein and detergents.