Daigger Scientific X-GAL is chromogenic substrate of β-Galactosidase used in combination with IPTG for detection of β-Galactosidase activity in bacterial colonies. X-GAL is cleaved at the B1-4 bond between galactose and the 5-Bromo-4chloro-3-indolyl portion of X-GAL by β-Galactosidase via hydrolysis. The cleavage of X-GAL resulted in the production of water insoluble blue dichloro-dibromo-indigo precipitate. In cloning strategies with vectors such as Lambda-11, M13amp18 and 19, PUC18 and 19, Pur222 the E.coli lacZ gene is transformed to lac+ cells. After transformation the cells show β-Galactosidase activity in the presence of media containing X-GAL and IPTG. The insertion of a DNA fragment into the cloning sites of the lacZ gene results in the disruption of β-Galactosidase activity leading to the appearance of white colonies. Non-recombinant cells product a blue indigo dye.

Soluble in DMSO and DMF. Store at 2-8°C. [5-Bromo-$chloro-3-indolyl-β-D-galactoside]

Key Features

• CAS No. 7240-90-6
• C₁₄H₁₅BrCINO₆
• MW 408.6
• Purity >99%