Description

5,5′-Dithiobis(2-Nitrobenzoic Acid), also known as DTNB or Ellman's reagent, is a critical chromogenic substrate widely used for the quantitative determination of sulfhydryl (-SH) groups. Its core value proposition lies in its ability to provide a sensitive, colorimetric assay for thiol quantification, making it indispensable for biochemical research and quality control. This compound is essential for researchers and manufacturers in the pharmaceutical, biotechnology, and diagnostic industries who require precise measurement of protein thiols, enzyme activity, and antioxidant capacity.

Application

• Thiol Group Quantification (Ellman's Assay): The primary application for the sensitive and specific colorimetric determination of free sulfhydryl groups in proteins, peptides, and other biological molecules.
• Enzyme Activity Studies: Used to monitor the activity of enzymes like acetylcholinesterase and other cholinesterases by measuring the release of thiocholine.
• Antioxidant Capacity Analysis: Employed in assays to measure the total antioxidant status or thiol-based antioxidant levels in biological samples and food products.
• Pharmaceutical Quality Control: Utilized in the analysis of drug substances and products that contain or interact with thiol groups to ensure potency and purity.
• Bioconjugation and Protein Labeling: Serves as a cross-linking agent or a reagent for introducing specific functional groups into proteins via disulfide bond formation.
• Diagnostic Reagent Manufacturing: A key component in the formulation of clinical diagnostic kits for measuring various biomarkers related to oxidative stress and liver function.

Basic Information

Product Name	5,5′-Dithiobis(2-Nitrobenzoic Acid)
CAS No.	69-78-3
Molecular Formula	C14H8N2O8S2
Molecular Weight	396.35 g/mol
Synonyms	DTNB; Ellman's Reagent; 3-Carboxy-4-nitrophenyl disulfide; 5,5'-Dithiobis(2-nitrobenzoate); Bis(3-carboxy-4-nitrophenyl) disulfide; 2-Nitro-5-mercaptobenzoic acid disulfide; 4,4'-Dithiobis(3-nitrobenzoic acid); 5,5'-Dithiodi(2-nitrobenzoic acid)
EINECS	200-714-4

Quality Control

Our 5,5′-Dithiobis(2-Nitrobenzoic Acid) is produced under strict quality management systems. Each batch undergoes rigorous analytical testing, including HPLC for purity and identity confirmation, to ensure it meets the high standards required for research and industrial applications. Certificates of Analysis (COA) detailing specific batch results are available upon request.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry place at a controlled room temperature (15-25°C). This product is light-sensitive (store away from light).

Specification

Item	Specification
Appearance	Yellow to yellow-green crystalline powder
Identification (IR)	Conforms to structure
Purity (HPLC)	≥ 98.0%
Melting Point	240 - 245 °C (with decomposition)
Absorbance (A412, pH 8.0)	≥ 13,600 M-1cm-1
Water Content (KF)	≤ 1.0 %
Residue on Ignition	≤ 0.1 %

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.