Skip to Content
Merck
All Photos(9)

Key Documents

View All Documentation

D8130

Sigma-Aldrich

5,5′-Dithiobis(2-nitrobenzoic acid)

≥98%, BioReagent, suitable for determination of sulfhydryl groups

Synonym(s):

3-Carboxy-4-nitrophenyl disulfide, 6,6′-Dinitro-3,3′-dithiodibenzoic acid, Bis(3-carboxy-4-nitrophenyl) disulfide, DTNB, Ellman’s Reagent

Sign Into View Organizational & Contract Pricing
All Photos(9)

About This Item

Linear Formula:
[-SC6H3(NO2)CO2H]2
CAS Number:
69-78-3
Molecular Weight:
396.35
Beilstein:
1896821
EC Number:
200-714-4
MDL number:
MFCD00007140
UNSPSC Code:
12352106
PubChem Substance ID:
24894189
NACRES:
NA.26

product line

BioReagent

Quality Level

200

Assay

≥98%

form

powder

mp

240-245 °C (dec.) (lit.)

suitability

suitable for determination of sulfhydryl groups

SMILES string

OC(=O)c1cc(SSc2ccc(c(c2)C(O)=O)[N+]([O-])=O)ccc1[N+]([O-])=O

InChI

1S/C14H8N2O8S2/c17-13(18)9-5-7(1-3-11(9)15(21)22)25-26-8-2-4-12(16(23)24)10(6-8)14(19)20/h1-6H,(H,17,18)(H,19,20)

InChI key

KIUMMUBSPKGMOY-UHFFFAOYSA-N

Looking for similar products? Visit Product Comparison Guide

General description

5,5′-Dithiobis(2-nitrobenzoic acid) is also called DTNB or Ellman′s reagent. It is a water soluble reagent, which interacts with thiol groups, and can be used conveniently at neutral pH. Thiolate anion (RS-) reacts with Ellman′s reagent (DTNB2-), to produce 2-nitro-5-thiobenzoate anion (TNB2-) and one mixed disulfide (R-S-TNB-). TNB2- has a high molar absorption coefficient, and absorbs at 412nm. This absorption is independent of pH, at pH> 7.3.

Application

Ellman′s reagent maybe used for acetylcholinesterase assay, and to specifically label cysteine residues. It is a sensitive reagent for measuring the free sulfhydryl content in proteins, peptides, and tissues.

Storage Class Code

11 - Combustible Solids

WGK

WGK 3

Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Personal Protective Equipment

dust mask type N95 (US), Eyeshields, Gloves

Certificates of Analysis (COA)

Search for Certificates of Analysis (COA) by entering the products Lot/Batch Number. Lot and Batch Numbers can be found on a product’s label following the words ‘Lot’ or ‘Batch’.

Already Own This Product?

Find documentation for the products that you have recently purchased in the Document Library.

Visit the Document Library

Ellman's reagent: 5,5'-dithiobis(2-nitrobenzoic acid)--a reexamination.
P W Riddles et al.
Analytical biochemistry, 94(1), 75-81 (1979-04-01)
Christian K Riener et al.
Analytical and bioanalytical chemistry, 373(4-5), 266-276 (2002-07-12)
Since its introduction in 1959, Ellman's reagent (5,5'-dithio-bis(2-nitrobenzoic acid)) has been the favorite reagent for spectrophotometric measurement of protein sulfhydryls. Meanwhile however, evidence has accumulated that many protein sulfhydryls give an incomplete reaction with Ellman's reagent, even during prolonged assay
Reassessment of Ellman's reagent.
P W Riddles et al.
Methods in enzymology, 91, 49-60 (1983-01-01)
Baharan Emam et al.
Particle and fibre toxicology, 17(1), 8-8 (2020-01-31)
Epidemiological studies have reported associations between elevated air pollution and autism spectrum disorders (ASD). However, we hypothesized that exposure to air pollution that mimics real world scenarios, is a potential contributor to ASD. The exact etiology and molecular mechanisms underlying
Venkaiah Betapudi et al.
Science translational medicine, 12(527) (2020-01-24)
Chemical warfare nerve agents are organophosphorus chemical compounds that induce cholinergic crisis, leaving little or no time for medical intervention to prevent death. The current chemical treatment regimen may prevent death but does not prevent postexposure complications such as brain
View All Related Papers

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

Contact Technical Service