Single Step (KRX) Competent Cells by Promega Corp.

Manufacturer Promega Corp.
The Single Step (KRX) Competent Cells are designed for efficient transformation and tightly controlled protein expression. These cells consolidate the best attributes of these two steps into one strain to evaluate protein expression in E. coli. Transformation efficiencies are greater than 108 cfu/μg, similar to other highly competent cells. The single step cells are available in single transformation size (50μl). KRX also can be used for blue/white screening.Single Step (KRX) is an E. coli K st... Read more


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Single Step (KRX) Competent Cells
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The Single Step (KRX) Competent Cells are designed for efficient transformation and tightly controlled protein expression.

These cells consolidate the best attributes of these two steps into one strain to evaluate protein expression in E. coli. Transformation efficiencies are greater than 108 cfu/μg, similar to other highly competent cells. The single step cells are available in single transformation size (50μl). KRX also can be used for blue/white screening.

Single Step (KRX) is an E. coli K strain that contains a chromosomal copy of the T7 RNA polymerase driven by a rhamnose promoter (rhaBAD) to provide dramatic control of the proteins expressed via a T7 promoter. Pre-induced expression protein levels are significantly lower than those of BL21(DE3)-derived strains. This feature facilitates cloning and expression of proteins toxic to E. coli.


Single Step (KRX) Competent Cells Features & Benefits:

  • Save Time - In two days, you can transform your vector into the Single Step (KRX) Competent Cells and be ready for protein expression.
  • Controlled Protein Expression - For overall expression of cloned proteins, the Single Step (KRX) Competent Cells provide dramatic control of expressed protein-coding regions.
  • Achieve High Yields - Protein expression levels were shown to be as high as or higher than levels expressed in BL21(DE3)-derived strains.
  • Blue/White Screening - Convenient method for detecting recombinant clones.