What Are TMB Peroxidase Substrates?

TMB is a chromogenic substrate used to stain in immunohistochemistry and is also used in ELISA. This substrate is also known as the 3,3’5,5 – Tetramethylbenzidine, TMBE substrate, chromogenic ELISA substrate. It looks like a white solid that turns into a blue-green liquid using ethyl acetate. It is susceptible to sunlight and fluorescent lights. There is no proof of TMB being cancerous. It is also a substrate for horseradish peroxidase. How this is connected with TMB is through combining horseradish peroxidase with hydrogen peroxide makes the blue color appear in TMB. The way TMB is used in ELISA experiments is like an electron donor. How this works is converting peroxides into water changing the color to blue. If we want to stop this reaction, we can change the color of TMB to yellow by using acid in it.










