Methyl Red sodium salt - ACS, ≥95% , CAS No.845-10-3

CAS: 845-10-3 Cat. No.: M102297 Molecular Weight: 291.28 Beilstein Registry Number: 16329 EC Number: 212-682-9
AVAILABLE TO ORDER
GRADE & PURITY ACS ? ACS grade — meets American Chemical Society specifications, the analytical benchmark in the US. Use for analytical and QC work needing ACS-defined purity. ≥95%
Synonyms
sodium;2-[[4-(dimethylamino)phenyl]diazenyl]benzoate | SCHEMBL4639900 | sodium 2-{2-[4-(dimethylamino)phenyl]diazen-1-yl}benzoate | FT-0628805 | BENZOIC ACID, 2-(2-(4-(DIMETHYLAMINO)PHENYL)DIAZENYL)-, SODIUM SALT | Benzoic acid, 2-[[4-(dimethylamino)pheny
Storage
Protected from light,Desiccated,Room temperature
Shipped In
Normal
 ·  off list, applied to all prices below.
Size
Status
Price
Qty
5g
M102297-5g
5
$9.90
25g
M102297-25g
4
$26.90
100g
M102297-100g
3
$76.90
500g
M102297-500g
8-12 wks(?) Production requires sourcing of materials. We appreciate your patience and understanding.
$344.90
Enter a quantity for the sizes you want to add.
🧪

Why this grade

ACS, ≥95% ACS for sensitive chromatographic and analytical workflows requiring minimal baseline interference.

🌡

Storage & shipping

Protected from light,Desiccated,Room temperature Ships Normal Check lot-specific COA for exact specifications.

📋

Quality documents

SDS, COA, datasheet, and spec sheet available for download. Lot-specific COA accessible via lot number lookup.

📚

Literature proof

Cited in 5 peer-reviewed publications across chromatography, organic synthesis, and cross-coupling reactions.

Overview

Methyl Red is an azo dye that indicates the presence of acid in the culture medium, which is formed due to fermentation of sugar by bacteria. This red dye is reduced to orange color in the presence of acid. Methyl Red has been used as a part of IMViC (indole, methyl red, Voges-Proskauer and citrate utilization or catalase production test). IMViC is a biochemical test performed to differentiate among the coliforms, specifically Escherichia coli and Enterobacter aerogene. Methyl red sodium salt is the sodium salt of methyl red synthetic dye, which belongs to the azo group of dyes.

Specifications

Synonyms
sodium;2-[[4-(dimethylamino)phenyl]diazenyl]benzoate | SCHEMBL4639900 | sodium 2-{2-[4-(dimethylamino)phenyl]diazen-1-yl}benzoate | FT-0628805 | BENZOIC ACID, 2-(2-(4-(DIMETHYLAMINO)PHENYL)DIAZENYL)-, SODIUM SALT | Benzoic acid, 2-[[4-(dimethylamino)pheny
Specifications & Purity
ACS, ≥95%
Biochemical and Physiological Mechanisms
Methyl Red is a pH indicator and it changes color at a pH of 5.5.pH indicator turning red under pH 4.4, yellow over pH 6.2, and orange in between those values. Azo dye used in microbiology to identify bacteria that produce stable acids through mixed acid
Storage
Protected from light, Desiccated, Room temperature
Shipped In
Normal
Grade
ACS
Note
Wherever possible, you should prepare and use solutions on the same day. However, if you need to make up stock solutions in advance, we recommend that you store the solution as aliquots in tightly sealed vials at -20°C. Generally, these will be useable for up to one month. Before use, and prior to opening the vial we recommend that you allow your product to equilibrate to room temperature for at least 1 hour. Need more advice on solubility, usage and handling? Please visit our frequently asked questions (FAQ) page for more details.
Purity
≥95%
Names and Identifiers
Pubchem Sid504763036
Pubchem Sid Urlhttps://pubchem.ncbi.nlm.nih.gov/substance/504763036
Canonical SmilesCN(C)C1=CC=C(C=C1)N=NC2=CC=CC=C2C(=O)[O-].[Na+]
IUPAC Namesodium;2-[[4-(dimethylamino)phenyl]diazenyl]benzoate
InChIKeyGNTPCYMJCJNRQB-UHFFFAOYSA-M
INCHI1S/C15H15N3O2.Na/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);/q;+1/p-1
Isomeric SMILES CN(C)C1=CC=C(C=C1)N=NC2=CC=CC=C2C(=O)[O-].[Na+]
Molecular Weight 291.28
Beilstein 16329
Reaxy-Rn 4065488
Reaxys-RN_link_address https://www.reaxys.com/reaxys/secured/hopinto.do?context=S&query=IDE.XRN=4065488&ln=

Documentation

📋 Safety Data Sheet (SDS)

Comprehensive hazard, handling, storage, and regulatory compliance document.

Download SDS →

✅ Certificate of Analysis (COA)

Lot-specific quality data. Enter your lot number to retrieve the exact COA.

Look up COA →

📊 Datasheet

Quick-reference summary of product specifications and applications.

View datasheet →

🔬 Specification Sheet

Full quality attributes and acceptance criteria for this grade.

View spec sheet →

Advanced Data

Taxonomic Classification

Taxonomy Tree

KingdomOrganic compounds
SuperclassOrganoheterocyclic compounds
ClassAzobenzenes
SubclassNot available
Intermediate Tree Nodes Not available
Direct ParentAzobenzenes
Alternative Parents Benzoic acids  Dialkylarylamines  Benzoyl derivatives  Aniline and substituted anilines  Carboxylic acid salts  Azo compounds  Amino acids  Propargyl-type 1,3-dipolar organic compounds  Carboxylic acids  Organooxygen compounds  Organic zwitterions  Organic sodium salts  Organic oxides  Hydrocarbon derivatives  
Molecular FrameworkAromatic homomonocyclic compounds
Substituents Azobenzene - Benzoic acid or derivatives - Benzoic acid - Benzoyl - Tertiary aliphatic/aromatic amine - Dialkylarylamine - Aniline or substituted anilines - Benzenoid - Monocyclic benzene moiety - Azo compound - Amino acid - Tertiary amine - Amino acid or derivatives - Carboxylic acid salt - Organic alkali metal salt - Organic 1,3-dipolar compound - Propargyl-type 1,3-dipolar organic compound - Carboxylic acid derivative - Carboxylic acid - Hydrocarbon derivative - Organonitrogen compound - Organooxygen compound - Organic oxide - Amine - Organic oxygen compound - Organic nitrogen compound - Organic zwitterion - Organic sodium salt - Organic salt - Aromatic homomonocyclic compound
DescriptionThis compound belongs to the class of organic compounds known as azobenzenes. These are organonitrogen aromatic compounds that contain a central azo group, where each nitrogen atom is conjugated to a benzene ring.
External Descriptors Not available
3D Structure
Interactive Chemical Structure Model





Certificates(CoA,COO,BSE/TSE and Analysis Chart)
C of A & Other Certificates(BSE/TSE, COO):
Analytical Chart:

Find and download the COA for your product by matching the lot number on the packaging.

11 results found

Lot NumberCertificate TypeDateItem
K2118529Certificate of AnalysisJul 25, 2025 M102297
K2118533Certificate of AnalysisJul 25, 2025 M102297
A2127197Certificate of AnalysisNov 15, 2024 M102297
G1915193Certificate of AnalysisMay 06, 2023 M102297
C2324117Certificate of AnalysisJan 28, 2023 M102297
C2324118Certificate of AnalysisJan 28, 2023 M102297
C2324119Certificate of AnalysisJan 28, 2023 M102297
C2528224Certificate of AnalysisJan 28, 2023 M102297
K2204915Certificate of AnalysisAug 30, 2022 M102297
B2309249Certificate of AnalysisOct 30, 2021 M102297
B2309294Certificate of AnalysisOct 30, 2021 M102297

Show more ⌵

Chemical and Physical Properties
SolubilitySoluble in water (800 mg/ml at 25°C), and slightly soluble in ethanol at (25°C).
SensitivityLight sensitive.
Molecular Weight291.280 g/mol
XLogP3
Hydrogen Bond Donor Count0
Hydrogen Bond Acceptor Count5
Rotatable Bond Count4
Exact Mass291.098 Da
Monoisotopic Mass291.098 Da
Topological Polar Surface Area68.100 Ų
Heavy Atom Count21
Formal Charge0
Complexity355.000
Isotope Atom Count0
Defined Atom Stereocenter Count0
Undefined Atom Stereocenter Count0
Defined Bond Stereocenter Count0
Undefined Bond Stereocenter Count0
The total count of all stereochemical bonds0
Covalently-Bonded Unit Count2
Citations of This Product
References
1. Tang Peixin, Si Yang, Song Xiyu, Sun Gang.  (2023)  Hierarchically porous bacterial cellulose nanofibrous membranes for selective adsorption and real-time colorimetric monitoring of volatile carboxylic acids.  CELLULOSE,      [PMID:] [10.1007/s10570-023-05632-8]
2. Li-Jun Xu, Xuan-Yu Shi, Meng-Ying Chai, Jian Ji, Zhi-Kang Xu, Ling-Shu Wan.  (2020)  Surface Metallization of Porous Polymer Materials for Multifunctional Applications.  LANGMUIR,      [PMID:31983209] [10.1021/acs.langmuir.9b03701]
3. Guo-Jun Wang, Bai-Heng Wu, Zhi-Kang Xu, Ling-Shu Wan.  (2019)  Janus polymer membranes prepared by single-side polydopamine deposition for dye adsorption and fine bubble aeration.  Materials Chemistry Frontiers,  (10): (2102-2109).  [PMID:] [10.1039/C9QM00253G]
4. Panpan Li, Jianguo Zhang, Yongfa Yu, Wenlin Jia, Shuang Zhao.  (2024)  A collaborative coagulation strategy for algae-laden and dye-containing water treatment.  Journal of Cleaner Production,      [PMID:] [10.1016/j.jclepro.2024.141146]
5. Wan-ru Liu, Yang Yang, Yue Xu, Bing Wang, Guang Zhang, Xin-yu Xu, Yuan-yuan Wang, Chun-min Ma, Na Zhang.  (2026)  Preparation of indicator cards for freshness detection of rice with four different processing degrees during storage based on olfactory visualization technology.  FOOD CHEMISTRY,      [PMID:41579539] [10.1016/j.foodchem.2026.147967]
Solution Calculators
Reviews

Customer Reviews

Need help choosing the grade?

Our grade selection guide covers purity, stabilizer status, and application suitability for all variants in our catalog.

View ACS grade guide →

Shall we send you a message when we have discounts available?

Remind me later

Thank you! Please check your email inbox to confirm.

Oops! Notifications are disabled.