High quality 6-Benzothiazolesulfonicacid, 2,2'-(1,2-hydrazinediylidene)bis[3-ethyl-2,3-dihydro-, ammonium salt(1:2) CAS NO.30931-67-0

In biochemistry, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) or ABTS is chemical compound used to observe the reaction kinetics of specific enzymes. A common use for it is in the enzyme-linked immunosorbent assay (ELISA) to detect for binding of molecules to each other.

It is commonly used as a substrate with hydrogen peroxide for a peroxidase enzyme (such as horseradish peroxidase) or alone with blue multicopper oxidase enzymes (such as laccase or bilirubin oxidase). Its use allows the reaction kinetics of peroxidases themselves to be followed. In this way it also can be used to indirectly follow the reaction kinetics of any hydrogen peroxide-producing enzyme, or to simply quantify the amount of hydrogen peroxide in a sample.