β-Galactosidase gene is widely used as a reporter gene for two major reasons: its protein product is extremely stable and resistant to protease mediated degradation in cellular contents, and secondly, the enzyme is easily assayed.  Chemediate provides easy and rapid colorimetric and/or fluorescent assays of β-galactosidase activity in the lysates of transfected cells.

β-Galactosidase converts colorless o-nitrophenyl-β-D-galactopyranoside (ONPG) into galactose and the chromophoric o-nitrophenol, yielding a bright yellow solution. The β-galactosidase activity of the solution can be quantified using a spectrophotometer or a microplate reader to determine the amount of o-nitrophenol converted at 420 nm.   Alternatively, Chemediate provides a fluorescent assay for detecting Alpha-galactosidase activity using 4-methylumbelliferyl-β -D-galactopyranoside as the substrate using fluorometer (at Ex/Em = 360/440 nm).