PR1MA™ X-GAL

PR1MA™ X-GAL [5-Bromo-4-chloro-3-indolyl-β-D-galactoside]

Common Name: 5-Bromo-4-chloro-3-indolyl-β-D-galactoside
CAS Number: 7240-90-6
Molecular Weight: 408.6
Chemical Formula: C₁₄H₁₅BrCINO₆
Solubility: DMSO and DMF
Storage Temperature: -20°C

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-4-chloro-3-indolyl portion of X-GAL by β-Galactosidase via hydrolysis. The cleavage of X-GAL results in the production of a water insoluble blue dichloro-dibromo-indigo precipitate. In cloning strategies with vectors such as Lambda-11, M13mp18 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 produce a blue indigo dye.


Water Content: 0.05% (K. Fisher)
Protect from light and moisture


Research or further manufacturing use only, not for food or drug use.

• Appearance: White Powder
• Identity: Conforms to structure
• Purity (HPLC): ≥ 98.0 %
• Solubility (2%, DMF): Clear and Colorless Solution
• Specific Rotation: -63.0 - -60.0 °
• Water Content (K.F): ≤ 0.5 %