Invitrogen™ One Shot™ BL21 Star™ (DE3) Chemically CompetentE. coli

Description

• One Shot BL21 Star (DE3) Chemically Competent E
• coli are designed for applications that require high-level expression of non-toxic recombinant proteins from low copy number, T7-promoter-based expression systems such as Champion pET vectors
• This strain offers enhanced mRNA stability due to a mutation in the RNaseE gene ( rne 131) that reduces levels of endogenous RNases and mRNA degradation, thereby increasing the stability of mRNA transcripts and increasing protein yield
• The BL21 Star strain has higher basal expression of heterologous genes than BL21 (DE3) strains, due to the increased stability of mRNA
• Thus, strains such as BL21-AI are recommended for toxic protein expression
• One Shot BL21 Star (DE3) Chemically Competent cells are provided at a transformation efficiency of >1 x 10 8 cfu/μg plasmid DNA
• BL21(DE3) is a derivative of the E
• coli B strain that does not contain the lon protease and is also deficient in the outer membrane protease OmpT
• The lack of two key proteases reduces degradation of heterologous proteins expressed in the strain
• Additionally, several other strain features make it especially suited for protein production, namely fast growth in minimal medium, a lower acetate production when grown in high glucose media, and the ability to reach high cell density
• The BL21 (DE3) E
• coli strain is one of the most popular host strains used to produce recombinant proteins and adapted in research or industrial applications
• This strain has been engineered to carry the λDE3 lysogen that contains the T7 RNA polymerase gene under the control of the lac UV5 promoter
• IPTG is required to induce expression of the T7 RNA polymerase cascade system that in turn transcribes the T7-promoter-regulated target gene
• One Shot BL21 Star (DE3) Chemically Competent E
• coli offer: • Transformation efficiency of >1 x 10 8 cfu/μg plasmid DNA • Ion and OmpT protease deficiency reduces degradation of recombinant protein • Optimized for use with low copy number, T7-promoter-based plasmids • rne 131 mutation that reduces levels of endogenous RNases and mRNA degradation • hsd S mutation that allows efficient transformation of unmethylated DNA • Fast growth in minimal medium and ability to reach high cell density Easy-to-use One Shot format BL21 Star (DE3) Chemically Competent E
• coli cells are supplied in the convenient, single-reaction One Shot format
• The single-tube, single-use format allows all steps of the transformation protocol, up to plating, to take place in the same tube, thereby helping save time and prevent contamination
• Genotype F – omp T hsd SB (r B –, m B –) gal dcm rne 131 (DE3) Find the strain and format that fits your needs • We offer other E
• coli strains for protein expression
• • For expression of toxic proteins, consider BL21-AI One Shot Chemically Competent E
• coli (Cat
• No
• C607003)
• • BL21 Star (DE3) and other strains are available in MultiShot formats for high throughput applications
• • We offer a variety of systems for the expression of recombinant proteins in E
• coli
• The Champion pET expression system provides the highest level of protein production available in any expression system
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