LB Agar Plates (Miller formulation) with Carbenicillin, 60 µg/mL X-Gal, 0.1 mM IPTG are used for growth and blue-white colony screening to detect vector-based, recombinant DNA clones in E. coli (colonies with inserts appear white and colonies with no inserts appear blue).
Carbenicillin selects for mutated or transformed cells carring the ß-lactamase (bla) gene, which confers resistance to ampicillin and carbenicillin. Carbenicillin is a semi-synthetic ampicillin analog that does not allow formation of satellite colonies. Typically, low-copy-number plasmids require less carbenicillin than high-copy-number plasmids.
Isopropyl ß-D-1-thiogalactopyranoside (IPTG) is non-metabolizable and induces gene expression by sequestering a repressor of the lac operon. X-Gal is the reporter substrate that can turn colonies blue.
Contains 1.0% (10 g/L) tryptone, 0.5% (5 g/L) yeast extract, 1.0% (10 g/L) sodium chloride, 100 µg/mL or 150 µg/mL carbenicillin, 60 µg/mL X-Gal, 0.1 mM IPTG, and 1.5% agar.