Synonym: 5-Bromo-3-indolyl β-D-galactopyranoside, Bluo-Gal
CAS Number 97753-82-7
Empirical Formula (Hill Notation) C14H16BrNO6
Molecular Weight 374.18
Beilstein Registry Number 1550140
MDL number MFCD00063691
PubChem Substance ID 24891417
Application
Chromogenic substrate suitable for identification of lac+ bacterial colonies. An alternative to 5-bromo-4-chloro-3-indolyl β-D-galactopyranoside (X-Gal), producing a darker blue color.
Suitable for use in selection of recombinant bacterial colonies with the lac+ phenotype.
General description
Bluo-Gal is a chromogenic substrate for β-galactosidase, used to determine the presence or absence of a cloned DNA insert in bacteria growing on agar plates. Bluo-Gal is designed to replace X-Gal in blue-white selection of recombinant bacterial colonies with the lac+ phenotype.
Principle
When Bluo-Gal is hydrolyzed by β-galactosidase, the resulting product will form a blue precipitate. Lac+ colonies grown in the presence of Bluo-Gal turn a deeper blue color more intense than X-Gal, allowing for easy differentiation between lac+ and lac- colonies.