5-Bromo-4-chloro-3-indoxyl-β-D-galactopyranoside

CAS: 7240-90-6

Ref. 3D-B-7150

Product Information

• Name: 5-Bromo-4-chloro-3-indoxyl-β-D-galactopyranoside
• Synonyms: X-beta-D-galactoside, .beta.-D-Galactopyranoside, 5-bromo-4-chloro-1H-indol-3-yl, 5-Bromo-4-chloro-1H-indol-3-yl beta-D-galactopyranoside, 5-Bromo-4-chloro-1H-indol-3-yl β-<span class="text-smallcaps">D</span>-galactopyranoside, 5-Bromo-4-chloro-3-C-indolyl-β-<span class="text-smallcaps">D</span>-galactopyranose, 5-Bromo-4-chloro-3-indolyl-.beta.-D-galactoside, 5-Bromo-4-chloro-3-indolyl-b-D-galactoside, 5-Bromo-4-chloro-3-indoyl-β-galactopyranoside, 5-Bromo-4-chloroindol-3-yl β-<span class="text-smallcaps">D</span>-galactopyranoside, 5-Bromo-4-chloroindol-3-yl β-<span class="text-smallcaps">D</span>-galactoside, Galactopyranoside, 5-bromo-4-chloroindol-3-yl, β-<span class="text-smallcaps">D</span>-, Indole, 5-bromo-4-chloro-3-(β-<span class="text-smallcaps">D</span>-galactopyranosyloxy)-, X-Gal, Xgal, β-<span class="text-smallcaps">D</span>-Galactopyranoside, 5-bromo-4-chloro-1H-indol-3-yl, β-D-Galactopyranoside, 5-bromo-4-chloro-1H-indol-3-yl, Indole, 5-bromo-4-chloro-3-(β-D-galactopyranosyloxy)-, Galactopyranoside, 5-bromo-4-chloroindol-3-yl, β-D-, 5-Bromo-4-chloro-1H-indol-3-yl β-D-galactopyranoside, 5-Bromo-4-chloroindol-3-yl β-D-galactopyranoside

Description

X-Gal is a chromogenic substrate for β-galactosidase, yielding a blue precipitate. X-Gal is an indicator for coliforms in culture media, as well as for the detection of coliforms (E. coli) in municipal water supplies and food products. X-Gal can be used in conjuction with the inducer IPTG, which binds and inhibits the lac repressor thus inducing β-galactosidase expression. X-Gal is the substrate of choice for blue-white selection of recombinant bacterial colonies with the lac+ genotype.
Upon hydrolysis, X-Gal yields a localized, insoluble, blue precipitate, making it exceptionally useful in blotting, immunocytochemical, and ELISA assays. 5-Bromo-4-chloro-3-indoxyl-β-D-galactopyranoside (X-β-D-galactoside, X-Gal) is a chromogenic indicator for β-galactosidase activity. The colorless product is cleaved by lactose-utilizing bacteriain liquid media or on agar plates and yields a blue-green colored precipiate.
X-Gal can also be used as a detecting agent for β-galactosidase activity in reporter gene assays or for identification of positive transformants on agar plates when using the α-complementation approach. Color formation is due to dimerization and oxidation of 5-bromo-4-chloro-3-hydroxyindole which results from enzymatic cleavage of X-Gal. The reaction proceeds only in the presence of oxygen, i.e. in aerobiccultures. Well detectable color bacterial colonies or liquid cultures is obtained within 16-48 h. In the presence of purified β-galactosidase, color develops within minutes to few hours.

• Brand: Biosynth

Chemical properties

• Molecular weight: 408.64 g/mol
• Formula: C₁₄H₁₅BrClNO₆
• Purity: Min. 99.0 Area-%