Redox Dyes

Enzymatic assay is a homogeneous assay method widely used to selectively determine the concentration of analytes in biological samples such as blood, urine, serum and plasma. In the field of clinical diagnostics, measuring the concentration of glucose in blood samples plays an important role in the management of diabetes and is performed by the combination of glucose oxidase/dehydrogenase and chemical reactions(Fig. 1). Dojindo offers a variety of chromogenic dyes that generate intense color in the presence of hydrogen peroxide or NADH.


New Trinder's Reagents are stable enough to use in both solution and test strip detection systems. They form highly stable purple or blue dyes through an oxidative coupling reaction with 4-Aminoantipyrine(4-AA) in the presence of hydrogen peroxide and peroxidase. The table below shows the maximum wavelength and molar absorptivity of each oxidized New Trinder's Reagent complex with 4-AA.


Product Name λmax(nm), pH Molar absorptivity
ADOS 542, 5.5-9.5 2.72 x 104
ADPS 540, 5.9-9.5 2.79 x 104
ALPS 561, 6.5-7.5 4.13 x 104
DAOS 593, 5.5-9.5 1.75 x 104
HDAOS 583, 5.5-9.5 1.73 x 104
Product Name λmax(nm), pH Molar absorptivity
MADB 630, 5.5-9.5 1.65 x 104
MAOS 630, 5.5-9.5 2.25 x 104
TODB 550, 5.5-9.5 3.80 x 104
TOOS 555, 5.5-9.5 3.92 x 104
TOPS 550, 5.5-9.5 3.74 x 104

Tetrazolium Salts are unique compounds with a slightly yellow color that generate intense orange to purple formazan dyes when reduced. This chemical property makes it possible to apply tetrazolium salts into a wide range of applications, for example, metabolism enzymatic assays, staining, cell viability monitoring and immunoassays in conjunction with an electron mediator. Below are the optical properties of formazan dyes of each tetrazolium salt.


Product Name λmax(nm), pH Molar absorptivity
WST-1 438 2.72 x 104
WST-3 433 2.79 x 104
WST-4 530 4.13 x 104
WST-5 550 1.75 x 104
WST-9 490 1.73 x 104
Product Name λmax(nm), pH Molar absorptivity
MTT 570 2.25 x 104
Nitro-TB(NBT) 530 3.80 x 104
TB 525 3.92 x 104
Application Products
Water-soluble WST-1
Non-water-soluble MTT
Application Products
Electron Mediator 1-Methoxy PMS
1-Methoxy PES
Ammine-reactive PES