X α-Gal [5 Bromo 4 Chloro 3 indolyl α-D-galactoside], 250 mg is a chromogenic substrate used to detect α-galactosidase activity in microorganisms and biochemical assays. When hydrolyzed by α-galactosidase, it produces a blue-colored compound, which can be easily quantified. This substrate is particularly useful in microbiological research, enzyme assays, and genetic studies, as it helps identify organisms that express α-galactosidase. X α-Gal is widely used in microbial screening, enzyme activity assays, and recombinant DNA studies where detection of α-galactosidase is necessary for the analysis of metabolic pathways or gene expression.