5-Bromo-4-chloro-3-indolyl-β-D-galactoside (X-Gal), Serva
C14H15BrClNO6 • Mw 408.6 • CAS [7240-90-6]
X-gal is a well-known histochemical substrate used to detect the β-galactosidase enzyme. Identification of lacf-colonies. X-gal is used to distinguish recombinant plasmids from parental vectors in cloning experiments using vectors containing the lacZ or lacZ [DMvP1] (-) peptide gene.
Upon hydrolysis, X-gal yields a localized, insoluble blue precipitate making it exceptionally useful in blotting, immunocytochemical, and ELISA assays. X-gal has been used for the detection of coliforms (E. coli) in municipal water supplies and food products. X-gal is often used in conjunction with IPTG (Isopropyl-β-D-thiogalactopyranoside) which binds and inhibits the lac repressor thus inducing β-galactosidase activity.
Stock solution: 20 mg/ml in DMF. Store in aliquots at -20 °C in the dark. For detection of transformants, use in final concentration of 40 µg/ml.
Assay (HPLC) min. 99 %
Storage Temperature: +2 °C to +8 °C
EINECS: 230-640-8 • WGK: 1 • HS: 29389090