Galactosidases are a group of enzymes that catalyze the hydrolysis of galactosides, which include lactose and various synthetic substrates. Among these, β-galactosidase is the most studied and widely used in both research and clinical diagnostics. This enzyme plays a critical role in carbohydrate metabolism by breaking down lactose into glucose and galactose, which can be utilized by cells for energy.

The measurement of galactosidase activity is essential for understanding metabolic disorders, such as lactose intolerance, and for applications in biotechnology, including the production of dairy products and biofuels. The activity of this enzyme is commonly measured using several assay methods, each with unique advantages and applications in research and industry.