SCS110 competent cells for generating unmethylated DNA improve quality and yield of miniprep DNA.

• Transformation efficiency of ≥5×10⁶ transformants/μg DNA
• Propagated DNA digestible by methylation-sensitive enzymes such as Xba I, Cla I, and EcoR II;Endonuclease-deficient cells (EndA-) improve miniprep quality
• Blue-white screening for recombinant plasmids
• Propagated DNA digestible by methylation-sensitive enzymes such as Xba I, Cla I, and EcoR II

SCS110 competent cells for generating unmethylated DNA are also an EndA- variant, which greatly improves the yield and quality of plasmid miniprep DNA.

CS110 is an endA– derivative of the JM110 strain. The SCS110 strain is ideal for preparing plasmid or phagemid DNA free of Dam or Dcm methylation so that the DNA can be restriction digested by one or more methylation sensitive restriction enzymes. SCS110 is deficient for two methylases (Dam and Dcm) found in most strains of E. coli. Dam methylase recognises the DNA sequence GATC and methylates the adenine residue at the N-6 position, while Dcm methylase recognises the DNA sequence CCAGG and CCTGG and methylates the internal cytosine at the C-5 position. SCS110 cells are endonuclease (endA) deficient, greatly improving the quality of miniprep DNA. SCS110 cells contain the lacIqZΔM15 gene on the F' episome, allowing bluewhite screening for recombinant plasmids.