Used as a non-metabolizable analog of lactose in biochemical research to study galactoside transport systems and β-galactosidase enzyme activity. Commonly employed in assays involving lactose permease and in the regulation studies of the lac operon in bacteria. Also serves as a blocking agent in lectin-binding experiments due to its affinity for certain galactose-specific lectins. Useful in glycosylation studies and as a reference compound in NMR analysis of carbohydrate derivatives.