Ponceau S

Jump to navigation Jump to search


A cherry red biological stain. Ponceau S is a diazo type dyes composed of the tetra sodium salt of 2,7-naphthalenedisulfonic acid. It forms a weakly acidic solution in water that can stain proteins. It has also been used as a Silk and Wool dye and as a former food colorant for maraschino cherries.

Chemical structure

Ponceau S.jpg

Synonyms and Related Terms

CI 27195


  • ThermoFisher: SDS

Physical and Chemical Properties

Soluble in water. Maximum absorption wavelength = 520 nm.

Composition C22H16N4O13S4.4Na
CAS 6226-79-5
Molecular Weight mol. wt. = 764.62

Resources and Citations=

  • R.Wolbers, G.Landry, "The Use of Direct Reactive Fluorescent Dyes for the Characterization of Binding Media in Cross Sectional Examinations" in Preprints of the AIC Meeting in Vancouver, 1987.
  • M.Johnson, E.Packard, "Methods Used for Identification of Binding Media in Italian paintings of the 15th and 16th Centuries" Studies in Conservation, 16:145-164, 1971.
  • The Merck Index, Susan Budavari (ed.), Merck Research Labs, Whitehouse Station, NJ, 12th Edition, 1996 Comment: entry 7750
  • Aldrich Chemical Catalog