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C6767

Sigma-Aldrich

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

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25 G
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About This Item

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

£24.40

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Product Name

Congo Red, Dye content ≥35 %

form

powder

Quality Level

200

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

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Application

  • Congo red has been used as a histochemical stain for the quantification of amyloid deposits in brain tissues.[1]
  • It has been used as a cell wall inhibiting agent in fungus Cryptococcus neoformans.[2]
  • It has also been used to study microstructural details in the cell walls of raw potato and fried potato using confocal microscopy.[3]

Biochem/physiol Actions

Congo red is a benzidine-based anionic diazo dye.[4] It is a histological dye which binds to many amyloid proteins and is used for the quantification of amyloid β-peptide aggregation.[5] Congo red also interacts with β-D-glucans, polysaccharides containing continuous β-(1→4)-linked D-glucopyranosyl units and some hemicellulosic galactoglucomannans.[6]

Pictograms

Health hazard
GHS08

Signal Word

Danger

Hazard Statements

H350,H361d

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

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Certificates of Analysis (COA)

Lot/Batch Number
BCCM2052
BCCK0878
BCCH1764
BCCF3019
BCCC7163

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Some changes in potato chips during frying observed by confocal laser scanning microscopy (CLSM).
Pedreschi F and Aguilera JM
Food Science and Technology International = Ciencia y tecnologia de Los Alimentos Internacional, 8, 197-201 (2002)
Kinetic study and equilibrium isotherm analysis of Congo Red adsorption by clay materials.
Chemical Engineering Journal, 148, 354-364 (2009)
Quantification of cerebral amyloid angiopathy and parenchymal amyloid plaques with Congo red histochemical stain.
Wilcock DM, et al.
Nature Protocols, 1, 1591-1591 (2006)
PKC1 is essential for protection against both oxidative and nitrosative stresses, cell integrity, and normal manifestation of virulence factors in the pathogenic fungus Cryptococcus neoformans.
Gerik KJ, et al.
Eukaryotic Cell, 7, 1685-1685 (2008)
Anat Frydman-Marom et al.
PloS one, 6(1), e16564-e16564 (2011-02-10)
An increasing body of evidence indicates that accumulation of soluble oligomeric assemblies of β-amyloid polypeptide (Aβ) play a key role in Alzheimer's disease (AD) pathology. Specifically, 56 kDa oligomeric species were shown to be correlated with impaired cognitive function in
View All Related Papers

Questions

1–3 of 3 Questions  

  1. hello, I would like to ask about this product, is it a powder or solution? thank you.

    1 answer

    1. As mentioned in the 'PROPERTIES' section, this product is supplied as a powder.

      Helpful?

  2. Why does the SDS for Congo Red list carcinogen as an OSHA hazard, (Section 2) but in Section 11 on carcinogenicity, it states that there is no component identified as a carcinogen?

    1 answer

    1. The reason that there is not an OSHA listing for carcinogens on most of SDS that have a hazard of a carcinogen hazard is because that section of the SDS is specifically for the OSHA regulated carcinogens, also referred to as the OSHA 13. Congo red at this time is not specifically called out  as a carcinogen by the other 3 Organizations listed (IARC, NTP, ACGIH) either. Congo red is listed by the European Classification Labeling & Packaging (CLP) Regulation (which is a pretty definitive guide for hazard classification), as a carcinogen. No other organizations have had the time to classify this material at this time. This is why it is only listed as a carcinogen in section 2 and in section 15.

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  3. What is the Department of Transportation shipping information for this product?

    1 answer

    1. Transportation information can be found in Section 14 of the product's (M)SDS.To access the shipping information for this material, use the link on the product detail page for the product.

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