Lactose (C12H22O11), also called milk sugar, is a disaccharide that consists of beta-D-galactose and alpha/beta-D-glucose through a beta1-4 glycosidic linkage. Lactose is the major sugar and makes up 2–8% of milk. Simple, direct and high-throughput assays for lactose determination find wide applications. BioAssay Systems' assay uses specific enzyme-coupled reactions in which lactose is cleaved and the resulting galactose forms a colored product. The color intensity at 570nm or fluorescence intensity at 530nm/585nm is directly proportional to the lactose concentration in the sample. This product is for Research Use only and is not intended for diagnostic purposes.