o-Nitrophenyl-β-D-galactoside (ONPG) is a colorimetric substrate for b-galactosidase. This product is hydrolyzed to o-nitrophenol by the enzyme. o-Nitrophenol is yellow in alkaline solution and can be quantitated at 410-420 nm 2 . o-Nitrophenyl-β-D-galactoside is a cell culture…

Sodium azide is used as a preservative for laboratory reagents; a bacteriostatic agent in storage solutions. Inhibits gram negative flora so is therefore included in culture media for the selective isolation of Streptococci and Staphylococci. It has been used to avoid bacterial contamination during…

Salicin is a substrate for β-glucosidase.