Skip to main content

Biebrich Scarlet

Biebrich Scarlet

Class: Azo
Ionisation: Acid

Chemical structure of Biebrich Scarlet

Common Name: Biebrich scarlet
Suggested Name: Biebrich scarlet
Other Names:

Croceine scarlet Ponceau B or BS

C.I. Number: 26905
C.I. Name: Acid red 66
Color: Red
Solubility Aqueous: Soluble
Solubility Ethanol: Soluble
Absorption Maximum: 504 (Conn), 506 (Gurr) 505 (Aldrich)
Empirical Formula: C22H14N4O7S2Na2
Formula Weight: 556.5


Biebrich scarlet is sometimes used as a plasma stain instead of Acid fuchsin in Masson's trichrome.

This dye should not be confused with the purified form of Sudan III, referred to as biebrich scarlet R.


  1. R. D. Lillie.
    Conn’s Biological Stains
    Williams & Wilkins, Baltimore, MD., U.S.A.
  2. Edward Gurr, 1971
    Synthetic dyes in biology, medicine and chemistry
    Academic Press, London, England.
  3. Aldrich chemical catalogue, 1992
    Aldrich Chemical Company, Milwaukee, WI, USA.