Beta-GLUCOSIDASE is a glucosidase enzyme which acts upon Beta1->4 bonds linking two glucose or glucose-substituted molecules (i.e., the disaccharide cellobiose). Beta-Glucosidases are required by organisms (some fungi, bacteria, termites) for consumption of cellulose. Lysozyme is also a Beta-glucosidase and is present in tears to prevent bacterial infection of the eye. In humans, lower activity of a Beta-glucosidase isoform (lysosomal gluco-cerebrosidase) has been related to Gaucher's disease and Parkinson's disease. Simple, direct and automation-ready procedures for measuring Beta-glucosidase activity are becoming popular in Research and Drug Discovery. This Beta-Glucosidase Assay Kit is designed to measure Beta-glucosidase activity directly in biological samples without pretreatment. The improved Method utilizes p-nitrophenyl-Beta-D-glucopyranoside that is hydrolyzed specifically by Beta-glucosidase into a yellow colored product (maximal absorbance at 405nm). The rate of the reaction is directly proportional to the enzyme activity.