SURE 2 competent cells are ideal for routine cloning of DNA with secondary structures.

• Lack components of the pathways that catalyse the rearrangement and deletion of nonstandard secondary and tertiary structures
• Allows for blue-white colour screening

Replicating eukaryotic DNA in prokaryotic cells can be problematic. Particular eukaryotic genes may contain inverted repeats or secondary structures, such as Z-DNA, that can be rearranged or deleted by E. coli DNA repair systems.

SURE competent cells are deficient in the E. coli genes involved in the rearrangement and deletion of DNA, thus improving cloning efficiencies of DNA containing irregular structures in prokaryotic cells. SURE cells are restriction minus (McrA-, McrCB-, McrF-, Mrr-, HsdR-) endonuclease (endA) deficient, and recombination (recB recJ) deficient.