Competent Cells for Unstable Clones - Details & Specifications

The SURE (Stop Unwanted Rearrangement Events) strain was engineered to allow the cloning of certain DNA segments that are “unclonable” in conventional E. coli strains. The SURE strain lacks components of the pathways that catalyze the rearrangement and deletion of nonstandard secondary and tertiary structures, including cruciforms (caused by inverted repeats) and Z-DNA, that occur frequently in eukaryotic DNA and that impede the cloning of the eukaryotic DNA in conventional strains (see Figure 1). SURE cells are restriction minus (McrA-, McrCB-, McrF-, Mrr-, HsdR-) endonuclease (endA) deficient, and recombination (recB recJ) deficient. The lacIqZΔM15 gene, on the F´ episome, allows blue white screening.

 

Figure 1. Stability of Inverted Repeats in E.coli Strains.

 

SURE Competent Cells

Efficiency:  =5 x 108 transformants/µg of pUC18 DNA
Resistant to kanamycin and tetracycline.


SURE Electroporation-Competent Cells


Electroporation-competent version of SURE Competent Cells.

Efficiency:  1 x 1010 transformants/µg of pUC18 DNA
Resistant to kanamycin and tetracycline.


SURE 2 Supercompetent Cells

High-efficiency derivatives of SURE (Stop Unwanted Rearrangement Events) competent cells.

Efficiency:
  1 x 109 transformants/µg of pUC18 DNA
Resistant to kanamycin, tetracycline, and chloramphenicol.