The TransforMax™ EC100D™ pir ⁺ Electrocompetent E. coli and TransforMax™ EC100D™ pir-116 Electrocompetent E. coli each constitutively express the π protein (the pir gene product) for replication of plasmids containing the R6Kγ origin of replication (R6Kγ ori). The cells are derived from Epicentre's TransforMax™ EC100™ Electrocompetent E. coli by P1 phage transduction with a strain containing the pir ⁺ or pir-116 gene linked to a dihydrofolate reductase (DHFR) marker.

The TransforMax EC100D pir ⁺ cells will maintain R6Kγ ori containing plasmids at approximately 15 copies per cell, ¹ for cloning of potentially toxic or unstable DNA sequences. The TransforMax EC100D pir-116 cells are for high-copy propagation of up to 250 rescue plasmid copies per cell. ¹

Benefits

• Accepts large clones for unbiased propagation and stability of large rescue clones.
• lacZΔM15 for blue/white screening of recombinants.
• Restriction minus [mcrA, Δ(mrr-hsdRMS-mcrBC)] enables efficient cloning of methylated DNA.
• Endonuclease minus ( endA1) to ensure high yields of DNA.
• Recombination minus ( recA1) for greater stability of large cloned inserts.

Genotypes

TransforMax EC100D pir ⁺ Electrocompetent E. coli:
F ^- mcrA Δ(mrr-hsdRMS-mcrBC) φ80dlacZΔM15 ΔlacX74 recA1 endA1 araD139 Δ(ara, leu)7697 galU galK λ- rpsL (Str ^R) nupG pir ⁺(DHFR)

TransforMax EC100D pir-116 Electrocompetent E. coli:
F ^- mcrA Δ(mrr-hsdRMS-mcrBC) φ80dlacZΔM15 ΔlacX74 recA1 endA1 araD139 Δ(ara, leu)7697 galU galK λ- rpsL (Str ^R) nupG pir-116(DHFR)

Transformation Efficiency

References

1. Metcalf, W.W. et al. (1994) Gene 138, 1.