β-Gal Assay Kit (Invitrogen™)

The β-Gal Assay Kit provides the reagents required to quickly measure the levels of active β-galactosidase expressed in cells transfected with plasmids expressing the lacZ gene. lacZ is a bacterial gene often used as a reporter construct in eukaryotic transfection experiments. The gene product of lacZ, β-galactosidase, is resistant to proteolysis in cellular lysates and its activity is easily assayed. β-galactosidase catalyzes the hydrolysis of β-galactosidase such as ortho-nitrophenyl-D-galactopyranoside (ONPG). Hydrolysis of ONPG to the ONP anion produces a bright yellow color with a peak absorbance at 420 nm that can be quantified using a spectrophotometer.
10.7 gene expression