Invitrogen™ One Shot™ BL21-AI™ Chemically CompetentE. coli

Description

• One Shot BL21-AI Chemically Competent E
• coli cells are designed for applications that require tight regulation and strong expression of toxic proteins from any T7-promoter-based expression systems. A derivative of the E
• coli B strain, BL21-AI does not contain the lon protease and is deliberately 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 these cells especially well 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
• BL21-AI E
• coli contain a chromosomal insertion of a cassette containing the T7 RNA polymerase (T7RNAP) into the ara B locus of the ara BAD operon, placing regulation of T7 RNAP under the control of the arabinose-inducible ara BAD promoter
• The ara B gene is deleted in this strain
• The presence of the tet A gene confers resistance to tetracycline and permits verification of strain identity using tetracycline
• The yield of recombinant protein obtained from BL21-AI is generally similar to that obtained from BL21 (DE3)
• BL21-AI, due it’s qualities and genomic background, was used to elucidate fundamental steps in the adaptation process of the CRISPR/Cas system
• One Shot BL21-AI Chemically Competent cells have a transformation efficiency of >1 x 10 8 cfu/μg plasmid DNA
• One Shot BL21-AI Chemically Competent E
• coli offer: • Transformation efficiency of >1 x 10 8 cfu/μg control plasmid DNA • Ion and OmpT protease deficiency that reduces degradation of recombinant protein • T7 RNA polymerase controlled by the tightly regulated arabinose-inducible ara BAD promoter • hsd S mutation that allows efficient transformation of unmethylated DNA • Ideal for inducing expression of toxic protein from any T7 promoter-based plasmid Easy-to-use One Shot format BL21-AI 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 S B (r B – , m B – ) gal dcm ara B::T7RNAP- tet A Find the strain and format that fits your needs We offer several E
• coli strains for protein expression
• 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
• Notes • To induce expression from the ara BAD promoter, use L-arabinose
• To repress basal expression from the ara BAD promoter, use glucose
• Even if glucose is absent, basal expression from is generally low
• • BL21-AI strain genome sequences available in the NCBI GenBank database under accession number CP047231 (Bhawsinghka et al
• 2020).