The CPRG assay kit is ideal to quantify low expression level of beta-Galactosidase. LacZ is one of the most frequently reporter gene used in transfection experiments. The LacZ encoded protein (beta-galactosidase, b-Gal), is very stable, resistant to proteolytic degradation and easily assayed. The levels of active beta-Gal actosidase expression can be quickly measured by its catalytic hydrolysis of CPRG (Chlorophenol red-b-D-galactopyranoside), substrate to a dark red product. The high sensitivity of this substrate improves the measurement of beta-Galactosidase activity when the reporter gene expression is low. (Absorbance at 570-595 nm). All the necessary reagents are provided in this assay kit and offer a rapid, simple and sensitive method to quantify spectrophotometrically the enzyme expression level in LacZ transfected cells. *Convenient for all transfection assays *Suitable for cultured cells and tissues *Simple, rapid and easy-to-use *Economical *Optimized with stable buffers