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Durazol Blue 4R

Durazol Blue 4R

Class: Azo
Ionisation: Acid

Chemical structure of Durazol Blue 4R

Common Name: Durazol blue
Suggested Name: Durazol blue 4R
Other Names:

Sirius supra blue F3R

C.I. Number:
C.I. Name:
Color: Blue
Solubility Aqueous: Very
Solubility Ethanol: Very
Absorption Maximum: 573 (Gurr)
Empirical Formula: C34H24N5O12S3Na3
Formula Weight: 860


A dye named durazol blue has been suggested as a replacement for methyl blue in Lendrum’s MSB. It is most likely to be this dye, durazol blue 4R. There is another dye named durazol blue 8G, but it is a copper phthalocyanine and is unlikely to be the dye meant. Unfortunately, the dye was not specifically identified and it is not clear what dye is meant.


  1. Edward Gurr, 1971
    Synthetic dyes in biology, medicine and chemistry
    Academic Press, London, England.
  2. Bancroft, J.D. and Stevens A.
    Theory and practice of histological techniques Ed. 2
    Churchill Livingstone, Edinburgh & London, UK.