The kit is designed to measure free thiols and disulfides in biological samples.Background: Bioquochem Thiol and Disulfide Assay Kit is recommended for estimations of oxidative stress levels in biological samples such as plasma. Since many proteins contain redox-sensitive free thiols, the identification and quantification of their different redox states gives us an idea of the oxidative stress level of the sample. The assay described here measures the formation of 2-nitro-5-thiobenzoate (TNB), which is proportional to the amount of reduced thiols in the sample that are oxidized by the 5,5'-dithiobis-2-nitrobenzoic acid (DTNB) through a non-specific reaction. The generated TNB ionizes to a dianion at alkaline pH and thus develops an intense yellow color with an absorbance maximum at 412 nm. On the other hand, the assay also allows the measurement of disulfides in the sample, thanks to NaBH4, which reduces these to thiols.Custom Assay Service Available! Please contact us for more information.