C6767

Congo Red

Dye content ≥35 %, Powder

• Synonym(s): Congo Red 4B, Cosmos Red, Cotton Red B, Cotton Red C, Direct Red 28, Direct Red R, Direct Red Y
• Empirical Formula (Hill Notation): C₃₂H₂₂N₆Na₂O₆S₂
• CAS Number: 573-58-0
• Molecular Weight: 696.66
• Colour Index Number: 22120
• Beilstein: 3894858
• EC Number: 209-358-4
• MDL number: MFCD00004028
• UNSPSC Code: 12171500
• PubChem Substance ID: 24892892
• NACRES: NA.47

Properties

• product name: Congo Red, Dye content ≥35 %
• form: powder
• composition: Dye content, ≥35%
• technique(s): titration: suitable
• color: red-brown
• pH: 6.7 (10 g/L)
• mp: >360 °C (lit.)
• solubility: H₂O: 1 mg/mL
• application(s): diagnostic assay manufacturing; hematology; histology
• storage temp.: room temp
• SMILES string: [Na+].[Na+].Nc1c(cc(c2ccccc12)S([O-])(=O)=O)\N=N\c3ccc(cc3)-c4ccc(cc4)\N=N\c5cc(c6ccccc6c5N)S([O-])(=O)=O
• InChI: 1S/C32H24N6O6S2.2Na/c33-31-25-7-3-1-5-23(25)29(45(39,40)41)17-27(31)37-35-21-13-9-19(10-14-21)20-11-15-22(16-12-20)36-38-28-18-30(46(42,43)44)24-6-2-4-8-26(24)32(28)34;;/h1-18H,33-34H2,(H,39,40,41)(H,42,43,44);;/q;2*+1/p-2/b37-35+,38-36+;;
• InChI key: IQFVPQOLBLOTPF-HKXUKFGYSA-L

Description

Application

• Congo red has been used as a histochemical stain for the quantification of amyloid deposits in brain tissues.
• It has been used as a cell wall inhibiting agent in fungus Cryptococcus neoformans.
• It has also been used to study microstructural details in the cell walls of raw potato and fried potato using confocal microscopy.

Biochem/physiol Actions

Congo red is a benzidine-based anionic diazo dye. It is a histological dye which binds to many amyloid proteins and is used for the quantification of amyloid β-peptide aggregation. Congo red also interacts with β-D-glucans, polysaccharides containing continuous β-(1→4)-linked D-glucopyranosyl units and some hemicellulosic galactoglucomannans.

Safety Information

• Pictograms: GHS08
• Signal Word: Danger
• Hazard Statements: H350,H361d
• Precautionary Statements: P201 - P202 - P280 - P308 + P313 - P405 - P501
• Hazard Classifications: Carc. 1B - Repr. 2
• Storage Class Code: 6.1C - Combustible acute toxic Cat.3 / toxic compounds or compounds which causing chronic effects
• WGK: WGK 3
• Personal Protective Equipment: dust mask type N95 (US), Eyeshields, Gloves