JM109 is a K strain that is recA– and endA– to minimize recombination and improve the quality of plasmid DNA. In addition, the cells carry the F´ episome, which allows blue/white screening. JM109 Competent Cells are available for convenient transformation in two efficiencies: High Efficiency at greater than 108cfu/μg for Cloning and Single Use, and Subcloning Efficiency at greater than 107cfu/μg.
For researchers doing more than one transformation, competent cells are available in standard format (200µl aliquots). For added convenience, single-use competent cells (50µl aliquots) also are offered.
JM109 Competent Cells are prepared according to a modified procedure of Hanahan.
JM109 Genotype: endA1, recA1, gyrA96, thi, hsdR17 (rk–, mk+), relA1, supE44, Δ( lac-proAB), [F´ traD36, proAB, laqIqZΔM15].
- Hanahan, D. (1985) DNA Cloning, Vol. 1, Glover, D., ed., IRL Press, Ltd., 109.