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C6767

Sigma-Aldrich

Congo Red

Dye content ≥35 %

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:
Molecular Weight:
696.66
Colour Index Number:
22120
Beilstein:
3894858
EC Number:
MDL number:
PubChem Substance ID:
NACRES:
NA.47

form

powder

Quality Level

composition

Dye content, ≥35%

technique(s)

titration: suitable

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

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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.

Packaging

25, 100 g in poly bottle

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.

Pictograms

Health hazard

Signal Word

Danger

Hazard Statements

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

Certificate of Analysis

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Certificate of Origin

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