The β-Galactosidase Enzyme Assay System with reporter lysis buffer is a convenient method for assaying β-galactosidase activity in lysates prepared from cells transfected with β-galactosidase reporter vectors such as the pSV-β-Galactosidase control vector.

• For measuring β-galactosidase enzyme activity in mammalian or bacterial cell extracts
• Non-isotopic assay
• Assay is usable in a 96-well plate format
• Reporter lysis buffer allows firefly luciferase, CAT, and β-galactosidase assays to be performed from the same cell extract

The standard assay is performed by adding a dilute sample to an equal volume of assay 2X buffer that contains the substrate ONPG (o-nitrophenyl-β-d-galactopyranoside). Samples are incubated for at least 30 minutes while the β-galactosidase hydrolyses the colourless substrate to o-nitrophenyl, which is yellow. The reaction can be terminated by addition of sodium carbonate, and spectrophotometry measures the absorbance at 420 nm.