Molekula
Methyl Red (C.I. 13020)
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
Methyl Red (C.I. 13020) is a synthetic pH indicator dye widely used in laboratories for titrations, microbiology, and analytical chemistry due to its distinct color change in acidic and alkaline conditions. It transitions from red to yellow between pH 4.4 and 6.2, making it ideal for precise pH detection. This chemical has a CAS number of 493-52-7, a molecular formula of C15H15N3O2, and a molecular weight of 269.30 g/mol. It is stable at ambient storage conditions and carries no signal word for hazard classification. Molekula supplies Methyl Red 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.
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.
-
25 g — £21.00 per pack ex VAT · £25.20 inc. VAT
-
500 g — £143.90 per pack ex VAT · £172.68 inc. VAT
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 | Red to Violet crystals/ crystalline powder |
| Melting Point | 178 - 180°C |
| Loss on Drying | ≤ 5.0% (110°C, 60min) |
| Dye Content | ⩾ 95.0% (Spectrophotometry) |
| Transition Range | pH 4.2 - 6.2 Pink-Yellow |
| Solubility at 0.1% (95% Ethanol) | Clear Red Solution |
| Absorption maxima (buffer pH4.2) | 523 - 528 nm |
| Absorption maxima (buffer pH6.2) | 427 - 437 nm |
Storage & handling
| Property | Value |
|---|---|
| Storage Temperature | Ambient |
| Acidity | Neutral |
Identification
| Property | Value |
|---|---|
| SKU | 27397766 |
| CAS Number | 493-52-7 |
| IUPAC Name | 2-[[4-(dimethylamino)phenyl]diazenyl]benzoic acid |
| EC Number | 207-776-1 |
| Molecular Formula | C15H15N3O2 |
| Molecular Weight | 269.30 |
| Exact Mass | 269.1164 |
| SMILES | CN(C)C1=CC=C(C=C1)N=NC2=CC=CC=C2C(=O)O |
| InChIKey | CEQFOVLGLXCDCX-UHFFFAOYSA-N |
| InChI | InChI=1S/C15H15N3O2/c1-18(2)12-9-7-11(8-10-12)16-17-14-6-4-3-5-13(14)15(19)20/h3-10H,1-2H3,(H,19,20) |
| PubChem CID | 10303 |
| REACH Code | Y113 |
| TSCA Listed | Yes |
| HTS Code | 2927.00.5000 |
| Tariff Code | 2927000090 |
Safety & GHS
Precautionary statements
- P280 Wear protective gloves/protective clothing/eye protection/face protection
Documents
Safety Data Sheets (SDS)
Available in English, English (US), French, German, Italian, Portuguese, 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-((4-(dimethylamino)phenyl)diazenyl)benzoic acid
- 2-(4-Dimethylaminophenylazo)benzoic acid
- 2-Carboxy-4'-(dimethylamino)azobenzene
- 4-Dimethylamino-2'-carboxylazobenzene
- Acid Red 2
- C.I. Acid Red 2
- Cerven methylova
- Methyl red
- O-METHYL RED
- p-(Dimethylamino)azobenzene-o-carboxylic acid
Frequently asked questions
What is Methyl Red (C.I. 13020) commonly used for?
Methyl Red is primarily used as a pH indicator in laboratories, particularly for titrations in the pH range of 4.4–6.2, and as a dye in microscopy and histology.
What is the chemical formula and molecular weight of Methyl Red?
The chemical formula is **C15H15N3O2**, and the molecular weight is **269.30 g/mol**.
How should Methyl Red be stored?
Store Methyl Red at **ambient temperature** in a tightly sealed container, away from direct sunlight and moisture.
What grades or purities of Methyl Red does Molekula supply?
Molekula supplies Methyl Red in **analytical grade** purity, suitable for laboratory and research applications.
Can Molekula supply Methyl Red in bulk quantities?
Yes, Molekula can supply Methyl Red in bulk, with quantities tailored to your specific requirements—please contact us for details.
What documentation comes with an order of Methyl Red?
Each order includes a **Certificate of Analysis (CoA)**, Material Safety Data Sheet (MSDS), and a product specification sheet.
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.