BL21-AI™ One Shot™ Chemically Competent E. coli

Catalog number:  C607003

 Related applications:

Protein Expression

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One Shot® BL21-AI™ E. coli are chemically competent cells designed for applications that require tight regulation and strong expression of toxic proteins from any T7 promoter-based expression systems. One Shot® BL21-AI™ Chemically Competent cells have a transformation efficiency of >1×108 cfu/ µg plasmid DNA.
• Ideal for inducing expression of toxic protein
• Gene expression is regulated by the addition of L-arabinose to culture
• Suitable for use with any T7 promoter-based plasmids
• Supplied in a convenient One Shot® format

Excellent Expression of Toxic Recombinant Proteins
One Shot® BL21-AI™ E. coli contains a chromosomal insertion of the gene encoding T7 RNA polymerase (T7RNAP) into the araB locus of the araBAD operon, placing regulation of T7 RNAP under the control of the arabinose-inducible araBAD promoter (1). Therefore, this strain is especially useful for the expression of genes that may be toxic to other BL21 strains where basal expression of T7 RNAP is leaky. The BL21-AI™ strain does not contain the Ion protease and is deficient in the outer membrane protease, OmpT. This genotype reduces degradation of heterologous proteins expressed in this strain. Finally, the yield of recombinant protein obtained from BL21-AI™ is generally similar to that obtained from other BL21 strains.

F-ompT hsdSB (rB- mB-) gal dcm araB::T7RNAP-tetA

Easy-to-use, Single Tube Format
The single tube, single use, format allows for all transformation steps to take place in the same tube, thereby helping to save time and prevent contamination.

Find the Strain and Format That You Need
We also offer many other different strains and formats of chemically competent cells and electrocompetent cells to help meet your specific transformation needs. For expression of non-toxic recombinant proteins, choose our One Shot® BL21 Star™ (DE3) chemically competent cells or One Shot® BL21 Star™ (DE3) pLysS chemically competent cells.

For Research Use Only. Not intended for animal or human diagnostic or therapeutic use.
For Research Use Only. Not for use in diagnostic procedures.



Competent Cell Type: Chemically Competent
Species: E. coli
Format: One Shot
Blue-White Screening: No
Bacterial or Yeast Strain: BL21-AI™
Cloning Methylated DNA: No
F' Episome (to make ssDNA): Lacks F' Episome
High Throughput Compatibility: Not High Throughput-Compatible (Manual)
Improves Plasmid Quality: No
Product Line: One Shot™
Product Size: 20 x 50 µL
Propagating ccdB Vectors: Not for ccdB vector propagation
Reduces Recombination: No
T1 Phage - Resistant (tonA): No
Transformation Efficiency: > 1x10^8

Contents & storage

BL21-AI™ Chemically Competent E. coli are provided in single-use, 50-µl aliquots, with S.O.C. medium and supercoiled control plasmid. Store competent cells at -80°C. All components are guaranteed stable for 6 months when properly stored.


Manuals & protocols