5,5′-Dithiobis(2-nitrobenzoic acid)

Crystalline

Reagent for determination of sufhydryl groups.5,5'-dithiobis-(2-nitrobenzoic acid) is widely utilized as a non-fluorescent probe to quantify the number or the concentration of thiol groups in a sample. It acts as a cleavable cross-linking agent. It finds an important application as a sensitive reagent for determining free sulfhydryl content in proteins, peptides, and tissues. It is also employed in high-performance liquid chromatography (HPLC) to determine the alkylthiol content.

5,5′-Dithiobis(2-nitrobenzoic acid) is a water soluble reagent mainly used for the derivatization of sulfhydryl groups.

5,5′-Dithiobis(2-nitrobenzoic acid) is an membrane-impermeant thiol/disulfide exchange blocker. It is also used to quantify the number or concentration of thiol groups in a sample.

ChEBI: 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.

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. Thiolate anion (RS^-) reacts with Ellman′s reagent (DTNB^2-), to produce 2-nitro-5-thiobenzoate anion (TNB^2-) and one mixed disulfide (R-S-TNB^-). TNB^2- has a high molar absorption coefficient, and absorbs at 412nm. This absorption is independent of pH, at pH> 7.3.