Description. One Shot BL21 Star (DE3) pLysS E. coli are chemically competent cells designed for applications that require high-level expression of non-toxic recombinant proteins from high copy number, T7 promoter-based expression systems (e.g., pRSET T7 vectors). One Shot BL21 Star (DE3) pLysS Chemically Competent cells have a transformation efficiency of >1 x 10 8 cfu/ µg plasmid DNA. Ultra BL21 (DE3) pLysS Competent Cells Warning: This product is intended for research use only. It is not to be used for diagnostic purposes in humans or animals. Page 1 of 2 v. 3 Product Cat. No. Transformations Ultra BL21 (DE3) pLysS Competent Cells, Tubes 43066 12 Description aliquot). Ultra BL21 (DE3) pLysS Competent Cells are chemically 3 About the Kit, Continued pLysS The pLysS plasmid carried by the BL21 Star™(DE3)pLysS strain produces T7 lysozyme to reduce basal level expression of the gene of interest. pLysS confers resistance to chloramphenicol (CamR) and contains the p15A origin. This origin allows pLysS to be compatible with pUC- or the BL21(DE3) and BL21(DE3)pLysS strains, respectively. In addition to the ? DE3 lysogen which allows high-level expression of T7-regulated genes, the BL21 StarZ strains also contain the rne131 mutation to enhance the expression capabilities of each strain. rne131 The rne gene encodes the RNase E enzyme, an essential, 1061 amino acid E. coli The BL21(DE3) pLysE Chemically Competent Cells produce T7 lysozyme to repress low-level transcription from the T7 promoter prior to IPTG induction, helping to stabilize inserts coding for deleterious products. These cells have a higher level of repression by T7 lysozyme, offering the greatest control over expression of inserts. BL21(DE3) Competent cells Chemically-competent E. coli cells supplied in 96-tube tray Instruction manual (v2.1) What is the difference between BL21 and BL21(DE3) competent E.coli cells? How should I store SOC Outgrowth Medium? The SOC I received with my competent cell