Substrate for β-Galactosidase that is converted, by the enzyme, into an insoluble indigoblue chromophore, darker than the one released by X-Gal. In histological applications, Bluo-Gal produces a precipitate in the form of fine birefringent crystals which, upon microscopic
examination under polarized light, emit a strong signal consisting of yellow reflected light, resulting in greatly enhanced sensitivity and better morphological resolution as compared with X-Gal. It is also used in Lac gene detection systems, in immunoblotting and immunocytochemical assays.
