The reaction starts with the conjugation of GSH with 5,5′-dithiobis-(2-nitrobenzoic acid) (DTNB) to form the mixed disulfide GS-TNB and the chromophore 5-thio-2-nitrobenzoic acid (TNB); this is ...

The spectrophotometric/microplate reader assay method for glutathione (GSH) involves oxidation of GSH by the sulfhydryl reagent 5,5′-dithio-bis(2-nitrobenzoic acid ...