5,5'-Dithiobis(2-nitrobenzoic acid)（DTNB），A biochemical analysis reagent

5,5'-Dithiobis(2-nitrobenzoic acid) (DTNB) is widely used in biochemical research and is a sensitive reagent for the determination of sulfhydryl groups in proteins, peptides and tissues.

DTNB can be mixed with sodium bicarbonate or phosphate buffer solution in a certain ratio and used as a coloring agent for the product acetylcholine. It is yellow, usually used for pesticide residue detection. The absorbance is used to reflect the enzyme activity and calculate the gallbladder. The inhibition rate of the alkaline esterase is finally used to determine whether the pesticide exceeds the standard.

In the existing rapid detection method of pesticide residues, DTNB is used as a separate chromogenic reagent for detecting cholinesterase activity. After the pesticide and cholinesterase in the sample inhibit the enzyme activity, DTNB is added. The agent and the substrate were then placed on a pesticide residue detector to measure the activity of cholinesterase and calculate the inhibition rate of cholinesterase. DTNB can also be combined with cholinesterase to form a special reagent for pesticide residue detection.

DTNB is used to detect free sulfhydryl groups and is a commonly used method for measuring serum cholinesterase in clinical applications. Cholinesterase hydrolyzes butyryl or propionylthiocholine to produce thiocholine and acetic acid. Thiocholine reacts with DTNB, a thiol color reagent, to produce the yellow compound 5-mercapto-2-nitrobenzoic acid (TNBA). The activity of the enzyme is calculated by colorimetric or continuous monitoring of the change in absorbance at 405-415 wavelength.

DTNB is also used to detect the content of sulfite in food. The detection reagent made with DTNB as a component can quickly detect the concentration of sulfite in food which has the characteristics of short time for color development and high detection efficiency.

Related links: 5,5'dithiobis (2-nitrobenzoic acid) DTNB