TMB Substrate

3,3'5,5’- tetramethylbenzidine (TMB) is a soluble chromogen substrate for horseradish peroxidase detection systems for ELISA. This is ready to use one component system and gives soluble blue color with peroxidase which absorbs at 653 nm; on acidification gives stable yellow color that absorbs at 45 nm. The extinction coefficient of blue color ( E653 nm = 3.9 x 14 mol-1 cm-1 ), and the yellow color is ( E45 nm = 5.9 x 14 mol-1 cm-1 ). TMB yields stable blue color as end product ., that can be measured at 65 nm; the color formation is function of time The reaction is stopped by adding acid solution it yields a yellow color that can be measured at 45 nm. This yellow color is 1.5 X more sensitive than blue color. This TMB solution contains TMB, 2.8 mMol L-1, Hydrogen Peroxide substrate, citrate buffer and non-toxic proprietary stabilizers.