Skip to Content
Merck

Skip To

C6277

Congo Red

Dye content, ≥85%, certified by the Biological Stain Commission, powder

Synonym(s):

Congo Red 4B, Cosmos Red, Cotton Red B, Cotton Red C, Direct Red 28, Direct Red R, Direct Red Y

Sign In to View Organizational & Contract Pricing.

Select a Size

Change View
Pack SizeSKUAvailabilityPrice

About This Item

Empirical Formula (Hill Notation):
C32H22N6Na2O6S2
CAS Number:
Molecular Weight:
696.66
UNSPSC Code:
12171500
NACRES:
NA.47
PubChem Substance ID:
EC Number:
209-358-4
MDL number:
Colour Index Number:
22120
Beilstein/REAXYS Number:
3894858
Pricing and availability is not currently available.
Technical Service
Need help? Our team of experienced scientists is here for you.
Let Us Assist


Product Name

Congo Red, certified by the BSC, BioXtra

agency

certified by the BSC

Quality Level

product line

BioXtra

form

powder

composition

Dye content, ≥85%

technique(s)

microbe id | staining: suitable

mp

>360 °C (lit.)

solubility

H2O: 10 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

Application

Congo red has been used for the staining of β amyloid peptides.
Certified for use as a counterstain for alum based hematoxylin and in the Highman or the Churukian modification of Puchtler′s amyloid stain.

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.

Compare Similar Items

View Full Comparison

Show Differences

1 of 1

This Item
C6767S4261S4136
technique(s)

microbe id | staining: suitable

technique(s)

titration: suitable

technique(s)

-

technique(s)

-

form

powder

form

powder

form

powder

form

powder

application(s)

diagnostic assay manufacturing
hematology
histology

application(s)

diagnostic assay manufacturing
hematology
histology

application(s)

diagnostic assay manufacturing
hematology
histology

application(s)

diagnostic assay manufacturing
hematology
histology

solubility

H2O: 10 mg/mL

solubility

H2O: 1 mg/mL

solubility

-

solubility

toluene: 1 mg/mL, clear, red

Quality Level

200

Quality Level

200

Quality Level

200

Quality Level

200

storage temp.

room temp

storage temp.

room temp

storage temp.

room temp

storage temp.

room temp


Still not finding the right product?

Explore all of our products under Congo Red


pictograms

Health hazard

signalword

Danger

Hazard Classifications

Carc. 1B - Repr. 2

Storage Class

6.1C - Combustible acute toxic Cat.3 / toxic compounds or compounds which causing chronic effects

wgk

WGK 3

ppe

Eyeshields, Gloves, type P3 (EN 143) respirator cartridges



Choose from one of the most recent versions:

Certificates of Analysis (COA)

Lot/Batch Number

Don't see the Right Version?

If you require a particular version, you can look up a specific certificate by the Lot or Batch number.

Already Own This Product?

Find documentation for the products that you have recently purchased in the Document Library.

Visit the Document Library



Long-term treatment of thalidomide ameliorates amyloid-like pathology through inhibition of ?-secretase in a mouse model of Alzheimer's disease.
He P, et al.
PLoS ONE, 8, e55091-e55091 (2013)
Alejandro Llanos-Chea et al.
Journal of pediatric gastroenterology and nutrition, 68(4), 509-516 (2018-11-13)
Enteric bacterial pathogens cause diarrheal disease and mortality at significant rates throughout the world, particularly in children younger than 5 years. Our ability to combat bacterial pathogens has been hindered by antibiotic resistance, a lack of effective vaccines, and accurate
Efficient imaging of amyloid deposits in Drosophila models of human amyloidoses.
Berg I, et al.
Nature Protocols, 5, 935-935 (2010)



Global Trade Item Number

SKUGTIN
C6277-25G04061833511060

Questions

1–3 of 3 Questions  
  1. looking for Congo Red stain, the one used in histopathology, but not sure which of the options is the best.

    1 answer
    1. The dry powder form allows for the preparation of Congo Red for various uses. The recommended dry dye for ordering is C6277 is currently undergoing BSC certification. Congo Red is a dye used for various staining procedures, mostly for staining of amyloid.

      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.

      Helpful?

  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.

      Helpful?

Reviews

No rating value

Active Filters