5,5’-Dithiobis(2-nitrobenzoic acid is an organic disulfide that results from the formal oxidative dimerisation of 2-nitro-5-thiobenzoic acid. An indicator used to quantify the number or concentration of thiol groups. It has a role as an indicator.
5,5′-Dithiobis(2-nitrobenzoic acid) is also called DTNB or Ellman′s reagent. It is a water soluble reagent, which interacts with thiol groups, and can be used conveniently at neutral pH.