The BioFX TMB High Definition One Component HRP Microwell Substrate contains 3,3’,5,5’‐tetramethylbenzidine (TMB) and is supplied as a ready‐to‐use solution. Peroxidase reacts with the substrate solution to produce a soluble blue reaction product that can be read at 370 nm or 620‐650 nm for ELISA applications. Stop solutions can be added to prevent further color development and reading the absorbance values at the desired wavelengths. Benefits of the BioFX? family of substrates include: Best-in-Class Kinetic Range, Outstanding Signal Generation, Reliable Durability, Consistent Detection.