Thermo Scientific Pierce TMB ELISA Substrates detect horseradish peroxidase (HRP) activity, yielding a blue color (Amax = 370nm and 652nm) that changes to yellow (Amax = 450nm) upon addition of a sulfuric or phosphoric acid stop solution.

TMB is the most popular chromogenic substrate for HRP detection in ELISA and is available in several formats. The Pierce 1-Step TMB Substrates are one-component substrates that require no preparation before use. Unlike other commercially available substrates, these products contain no DMF or DMSO.