A. Aitken, M. Learmonth
2009
Citations
2
Influential Citations
47
Citations
Journal
Journal name not available for this finding
Abstract
Ellman’s reagent 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) was first introduced in 1959 for the estimation of free thiol groups (1). The procedure is based on the reaction of the thiol with DTNB to give the mixed disulfide and 2-nitro-5-thiobenzoic acid (TNB) which is quantified by the absorbance of the anion (TNB2–) at 412 nm. The reagent has been widely used for the quantitation of thiols in peptides and proteins. It has also been used to assay disulfides present after blocking any free thiols (e.g., by carboxymethylation) and reducing the disulfides prior to reaction with the reagent (2,3). It is also commonly used to check the efficiency of conjugation of sulfhydryl-containing peptides to carrier proteins in the production of antibodies.