TMB+ One-Step Substrate System is a stabilized, ready-to-use chromogenic substrate solution for ELISA when peroxidase
is the enzyme label. The TMB+ One-Step Substrate System contains 3,3'-5,5' tetramethylbenzidine (TMB) and hydrogen peroxide in an organic solvent/buffer solution. Upon oxidation, TMB forms a blue reaction product that can be measured at 605 nm. Upon acidification (to stop the enzymatic reaction) the reaction product turns yellow with an absorbance peak at 450 nm.