Bluo-Gal (halogenated indolyl-β-galactoside) is an alternative histochemical substrate for β-galactosidase that produces a darker blue color than X-gal, the more frequently used substrate. As with X-gal, Bluo-Gal produces blue (lac+) bacterial colonies and blue (lac+) viral plaques. Bacteria containing active β-galactosidase produce blue colonies when grown on plates containing Bluo-Gal.

Bluo-Gal can also be used as a substrate with the streptavidin-β-galactosidase conjugate in both immunoblot and immunocytochemistry assays. In the presence of β-galactosidase, Bluo-Gal yields a blue precipitate, which is insoluble in alcohols and xylenes. Bluo-Gal is soluble in dimethylformamide.

Primary applications
• Blue-white screening (deeper blue as compared to X-gal)—detect functional β-galactosidase (reporter gene expression)
• Histochemical detection of β-galactosidase activity in fixed tissues
• Bluo-Gal overlay assay

Find the media format that fits your needs
Ready-to-use media formulations are available, such as LB Broth, Terrific Broth, or S.O.C recovery medium.
IPTG is available for blue-white screening.
Explore other media formats for bacterial growth.