The one component 3,3’,5,5’-tetramethylbenzidine (TMB) substrate is supplied in a ready-to-use solution. Peroxidase reacts with the TMB 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: Prolonged stability, Increased sensitivity, Negligible backgrounds, Ease of manufacturing.