Ponceau 6R

  Ponceau 6R, or Crystal ponceau 6R, Crystal scarlet, Brilliant crystal scarlet 6R, Acid Red 44, or C.I. 16250, is a red azo dye. It is soluble in water and slightly soluble in ethanol. It is used as a food dye, with E number E126. It is also used in histology, for staining fibrin with the MSB Trichrome stain. It usually comes as disodium salt.

Additional recommended knowledge

Essential Laboratory Skills Guide

Correct Test Weight Handling Guide: 12 Practical Tips

Weighing the right way

Amaranth is a closely related azo dye, also usable in trichrome staining.

Its CAS number is [2766-77-0] and its SMILES structure is OC1=C(N=N C3=C(C=CC=C4) C4=CC=C3)C2=C (C=C(S(=O) ([O-])=O)C=C2 S(=O)([O-]) =O)C=C1.

See also

• Ponceau family of Azo dyes