[Method of determining the activity of beta-galactosidase with lactose as substrate]

A method for estimating beta-galactosidase activity (beta-D-galactosidase-galactohydrolase, EC 3.2.1.23) with lactose as substrate was developed. The glucose formed as a result of lactose hydrolysis was determined by glucoseoxidase method with potassium ferrocyanide as a substrate-dye. The method is convenient, simple and reproducible, as well as gives an opportunity to characterize the enzyme due to its ability to hydrolyze lactose that is of great value when putting the enzyme into practice.