Thiols, compounds that contain sulfhydryl group, are powerful reducing agents capable of acting as antioxidants, enzyme cofactors, and neuromodulators. The SensoLyte® Thiol Quantitation Assay Kit utilizes the widely used Elmann’s reagent for colorimetric measurement of thiol concentrations. The sulfhydryl group of thiol reacts with Ellman’s Reagent [5, 5’-dithiobis (2-nitrobenzoic acid)] and generates 2-nitro-5-thiobenzoic acid (TNB) producing a yellow color that can be detected at absorbance 420 nm. The intensity of the color produced is proportional to thiol concentration. Kit Size: 500 assays (96-well plate).