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 (DTNB2-), to produce 2-nitro-5-thiobenzoate anion (TNB2-) and one mixed disulfide (R-S-TNB–). TNB2- has a high molar absorption coefficient, and absorbs at 412nm. This absorption is independent of pH, at pH> 7.3.
Ellman′s reagent maybe used for acetylcholinesterase assay, and to specifically label cysteine residues. It is a sensitive reagent for measuring the free sulfhydryl content in proteins, peptides, and tissues.
1, 5, 10, 25, 100 g in poly bottle
500 mg in glass insert