Ellman's Reagent, 5,5'-Dithiobis(2-nitrobenzoic acid), 100 g

5,5'-dithio-bis-(2-nitrobenzoic acid) (DTNB)   Ellman's reagent is a versatile, water-soluble compound for quantifying free sulfhydryl groups in solution. It reacts with a free sulfhydryl group to yield a mixed disulfide and 2-nitro-5-thiobenzoic acid (NTB), a measurable yellow colored product at 412nm.   Ellman's reagent is very useful as a free sulfhydryl assay reagent due to its high specificity for -SH groups at neutral pH, high molar extinction coefficient and short reaction time.   Synonyms: DTNB; 5,5'-Dithio-bis(2-nitrobenzoic acid); Ellman’s Reagent; 3-Carboxy-4-nitrophenyl disulfide   MOLECULAR BIOLOGY GRADE   PubChem Chemical ID:  6254   Yellow crystalline powder that is used for the colorimetric determination of thiol groups in biological samples. DTNB is fairly soluble in water.   Store at 2-8°C and protect from light and humidity. Features Highly stable and water soluble Quick and simple assay CAS#: 69-78-3 Molecular Formula:  C₁₄H₈N₂O₈S₂ Molecular Weight: 396.36 g/mol  Applications Quantification of free sulfhydryl residues