CulGenex™ Antibiotic and Chromogenic Supplements are recommended for use in the selective and/or differential growth of recombinant strains of Escherichia coli used for genetic research. Antibiotics such as ampicillin, kanamycin, and carbenicillin are typically used as selective agents to isolate strains that have taken up genes (e.g. plasmids) coupled to a gene encoding for resistance. X-GAL, used in conjunction with IPTG, is intended for the colorimetric detection of beta-galactosidase activity in recombinant strains.