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Can carbenicillin be substituted for ampicillin when selecting for the pGEM® Vectors?

Yes, the antibiotic carbenicillin can be substituted for ampicillin in antibiotic selection plates when E. coli cells such as JM109 cells (Cat.# L2001) are transformed with or carry any of our pGEM® Vectors. The ß-lactamase (bla) gene, which confers resistance to ampicillin, also confers resistance to carbenicillin, a semi-synthetic ampicillin analog. In some cases, carbenicillin may be preferred, as it tends to be more stable than ampicillin (i.e., less likely to break down in the presence of ß-lactamases). and can reduce the growth of satellite colonies on plates during long-term incubations (1). Dissolve carbenicillin in a 50% ethanol solution and use at a final concentration of 100µg/ml in solid media.

Reference

  1. Sambrook, J. and Russell, D.W. (2001) In: Molecular Cloning: A Laboratory Manual, Third Edition Cold Spring Harbor Laboratory Press, New York, 1.148.