JM Competent Cells are recombination- and E. coli K12 restriction-proficient.

• Blue-white color screening possible for recombinant plasmids
• Transformation efficiency >1×10⁸ transformants/µg DNA
• High quality competent cells for preparing methylation-free DNA
• The SCS110 strain lacks both dam and dcm activity, and DNA propagated in this strain can be digested by methylation-sensitive enzymes such as Xba I, Cla I and EcoR II
• JM110 cells contain the lacIqZΔM15 gene on the F' episome, allowing blue-white screening for recombinant plasmids

JM101 competent cells are a classic E. coli strain for economical cloning when you don’t need supercompetent efficiencies. E. coli K12 JM101 is a recombination- and E. coli K12 restriction-proficient host strain. Intrinsic antibiotic resistance aids cell selection after a complete and successful transformation.

JM109 competent cells are a classic E. coli strain for routine cloning and plasmid maintenance. E. coli K12 JM109 is recombination- and endonuclease-deficient, improving insert stability and quality of miniprep DNA, respectively. The hsdR mutation prevents the cleavage of cloned DNA by the EcoK endonuclease system.

JM110 - Most E. coli hosts contain both DNA adenine methylation (Dam) and DNA cytosine methylation (Dcm) genes. These genes code for proteins that methylate specific sequences when DNA is propagated, making subsequent digestion with methylation-sensitive restriction enzymes impossible. The SCS110 strain, lacks both dam and dcm activity. DNA propagated in this strain can be digested by methylation-sensitive enzymes such as Xba I, Cla I and EcoR II.

The JM110 strain is useful for preparing plasmid or phagemid DNA that is free of Dam or Dcm methylation so that the DNA can be restriction digested by one or more methylation-sensitive restriction enzymes. JM110 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. JM110 cells contain the lacIqZΔM15 gene on the F' episome, allowing blue-white screening for recombinant plasmids.