This presentation will describe the use of lactase tablets in enzyme kinetics. Lactase tablets were used because they are a source of very cheap enzyme compared to beta-galactosidase from a biochemical supply company. The presentation will describe how to run the reaction at the optimum pH of the enzyme (pH 4.5) or at the pH which produces color from the product (pH 7.5). At pH 7.5, color is produced when the ortho-nitrophenyl-beta-galactoside (ONPG) is hydrolyzed to galactose and the yellow ortho-nitrophenolate ion. When the reaction is run at pH 4.5, samples of the reaction mixture must be treated with base to give color. This paper will describe the conditions and student results when using ONPG with lactase tablets. Another major problem is how to measure the enzyme kinetics of lactase with its natural substrate of lactose. This paper will also describe efforts to study the enzyme kinetics of lactase tablets on the hydrolysis of lactose.