1.New Trinder’s Reagents (Oxidase system)
New Trinder‘s Reagents, which are highly water-soluble aniline derivatives, are applicable for the colorimetric determination of hydrogen peroxide. In the presence of a coupler such as 4-aminoantipyrine(4-AA), the Trinder‘s reagents are oxidized with peroxidase and two molecules of hydrogen peroxide and are developing the color to purple or blue.
2.Tetrazolium Salts and Electron Mediators (Dehydrogenase system)
Tetrazolium salts have been developed to determine dehydrogenase activity which oxidizes its substrate and reduces its co-enzyme, NAD or NADP and produce NADH or NADPH. The colored formazan dyes are produced upon reduction of NADH in the presence of an electron mediator. To perform the homogenous assay in aqueous condition, Water-Soluble Tetrazolium salts (WST) are widely applied for the diagnostic analysis and life science research due to much improved water-solubility than water insoluble tetrazolium salts, such like NBT and INT.