Molekula
5,5'-Dithio-bis(2-nitrobenzoic acid)
Supplying 4,500+ customers in over 80 countries
ISO 9001:2015 & ISO 14001:2015 certified · Supplying laboratories and industry since 2000 · Listed pack sizes are a starting point — we manufacture, source and repack to the quantity you need
5,5'-Dithio-bis(2-nitrobenzoic acid), also known as DTNB or Ellman's reagent, is a chemical used to quantify free thiol groups in biological samples. It reacts specifically with sulfhydryl groups to produce a yellow-colored anion detectable at 412 nm. It also serves as a colorimetric indicator in laboratory assays measuring cholinesterase and other enzyme activities. CAS: 69-78-3, Molecular Formula: C14H8N2O8S2, Molecular Weight: 396.35 g/mol, Storage: 2 to 8 °C, Signal Word: Warning. Molekula supplies 5,5'-Dithio-bis(2-nitrobenzoic acid) from research to bulk quantities with full documentation and ISO 9001:2015 traceability.
Example image for illustration only. Other packaging and pack sizes are available.
Often bought together
Pricing & pack sizes
These pack sizes aren't a limit. Molekula manufactures, sources and repacks to order — if you need 500 kg and only see 1 kg listed, . We quote from grams to multi-tonne.
Need a different size? Add the nearest pack and change the size in your basket — we price it at the same rate per unit.
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5 g — $79.80 per pack
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25 g — $295.60 per pack
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500 g — $2,451.00 per pack
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1 kg — $4,142.00 per pack
Need a different quantity or pack?
Tell us how much you need and when — drums, IBCs, sacks or a one-off bulk lot. We'll manufacture or source it and come back with a price.
Prices exclude VAT/sales tax and shipping.
Specifications
| Property | Value |
|---|---|
| Appearance | Straw yellow powder |
| Water | ≤0.5% |
| Purity (HPLC) | ⩾ 99.0% |
| Identification | Conforms to reference |
| Solubility | soluble (1% in Methanol) - light yellow solution |
| Assay (Titration) | 98.0 - 101.0% |
| Nitrogen (N) | 16.7 - 17.6% |
Storage & handling
| Property | Value |
|---|---|
| Storage Temperature | 2 to 8 °C |
| Acidity | Acid |
For research use only. Not for human use.
Identification
| Property | Value |
|---|---|
| SKU | 27025260 |
| CAS Number | 69-78-3 |
| IUPAC Name | 5-[(3-carboxy-4-nitrophenyl)disulfanyl]-2-nitrobenzoic acid |
| EC Number | 200-714-4 |
| Molecular Formula | (-SC6H3(NO2)COOH)2 |
| Molecular Weight | 396.35 |
| Exact Mass | 395.9722 |
| SMILES | C1=CC(=C(C=C1SSC2=CC(=C(C=C2)[N+](=O)[O-])C(=O)O)C(=O)O)[N+](=O)[O-] |
| InChIKey | KIUMMUBSPKGMOY-UHFFFAOYSA-N |
| InChI | 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) |
| PubChem CID | 6254 |
| REACH Code | Y113 |
| TSCA Listed | Yes |
| HTS Code | 2930.90.2900 |
| Tariff Code | 2930909599 |
Safety & GHS
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Health Hazard
GHS07
Hazard statements
- H315 Causes skin irritation
- H319 Causes serious eye irritation
- H335 May cause respiratory irritation
Precautionary statements
- P261 Avoid breathing dust/fume/gas/mist/vapours/spray
- P280 Wear protective gloves/protective clothing/eye protection/face protection
- P302+352 IF ON SKIN: Wash with soap and water
- P305+351+338 IF IN EYES: Rinse with water for several minutes. Remove contact lenses if present and easy to do. Continue rinsing
Documents
Safety Data Sheets (SDS)
Available in English, French, German, Italian, Spanish.
Certificate of Analysis (CoA) by batch
Enter a lot or batch number to retrieve the CoA for that specific batch. We can generate one from spec data if no PDF is on file.
Synonyms
- 2,2'-Dinitro-5,5'-dithiodibenzoesaeure
- 2,2'-Dinitro-5,5'-dithiodibenzoic acid
- 3,3'-Dithiobis(6-nitrobenzoic acid)
- Benzoic acid, 3,3'-dithiobis[6-nitro-
- Dithiobisnitrobenzoic acid
- Dithionitrobenzoic acid
- DTNB
- Ellman Reagent
- Ellman's Reagent
- Reagent, Ellman's
Frequently asked questions
What is 5,5'-Dithio-bis(2-nitrobenzoic acid) used for?
It is primarily used in biochemical assays to measure free thiol groups, particularly in the determination of glutathione levels.
What is the chemical formula and molecular weight?
The formula is C14H8N2O8S2 and the molecular weight is 396.35 g/mol.
How should this compound be stored?
Store at 2 to 8 °C in a cool, dark place to prevent degradation.
What grade is available?
Available in analytical grade for laboratory use.
Can Molekula supply this in bulk?
Yes, Molekula can supply larger quantities upon request; please contact our sales team for bulk pricing and availability.
What documentation comes with the order?
Each order includes a Certificate of Analysis (CoA) and Safety Data Sheet (SDS) with the shipment.
Ready to order or need a custom pack?
Tell us the product, grade, and quantity — Molekula usually responds within one working day with pricing and lead time.