β-Galactosidase assay is for determining the β-galactosidase activity in the lysates of cells transfected with a β-galactosidase expression construct. It uses chlorophenol red-β-D-galactopyranoside (CPRG), which is up to 10 times more sensitive than the classic O-nitrophenyl-β-D-galactopyranoside (ONPG) β-Galactosidase assays. This increased sensitivity makes it simpler to measure β-galactosidase activity in cells that are difficult to transfect or have low β-galactosidase activity expression. β-Galactosidase activity is measured using a spectrophotometer or a microplate reader to determine the amount of substrate converted at 570 to 595 nm.

• Colorimetric assay
• 10X more sensitive than ONPG assays
• Scalable
• Monitor levels of transfection in cells