ABTS is a radical cation and a peroxidase substrate. It is used to assess antioxidant capacity in the Trolox equivalent antioxidant capacity (TEAC) assay. It is blue in the presence of sodium persulfate or metmyoglobin but decolorizes upon incubation with antioxidants, and the antioxidant capacity can be determined spectrophotometrically. ABTS has also been used as an enzyme substrate in ELISAs. Upon incubation with a peroxidase, it produces a soluble green product that can be quantified by colorimetric detection at 405 nm.

Providing storage is as stated on the product vial and the vial is kept tightly sealed, the product can be stored for up to 24 months.
Wherever possible, you should prepare and use solutions on the same day. However, if you need to make up stock solutions in advance, we recommend that you store the solution as aliquots in tightly sealed vials at -20°C. Generally, these will be useable for up to one month. Before use, and prior to opening the vial we recommend that you allow your product to equilibrate to room temperature for at least 1 hour.