TMB (3, 3', 5, 5' - Tetramethylbenzidine) is the most sensitive colorimetric substrate for peroxidase detection

TMB Membrane Peroxidase is supplied as 3 solutions for simple mix-and-use preparation. The substrate may be adapted as a soluble substrate for ELISA by omitting TMB Membrane Enhancer.

It produces a deep blue stable precipitate at the reaction site in the presence of peroxidase-labeled conjugates, enabling detection of as little as 50 pg of peroxidase. It is recommended for membrane assays and dot blots.