The Chemical Entities of Biological Interest (ChEBI) ontology is downloaded weekly from EMBL-EBI at http://www.ebi.ac.uk/chebi/. The data is made available under the Creative Commons License (CC BY 3.0, http://creativecommons.org/licenses/by/3.0/). For more information see: Degtyarenko et al. (2008) ChEBI: a database and ontology for chemical entities of biological interest. Nucleic Acids Res. 36, D344–D350.
An organic sodium salt that is the disodium salt of 2-amino-5-[(4-amino-3-sulfophenyl)(4-imino-3-sulfocyclohexa-2,5-dien-1-ylidene)methyl]-3-methylbenzene-1-sulfonic acid. It is used in the Van Gieson method in conjunction with picric acid to demonstrate collagen fibres red, and in Masson's trichrome to colour smooth muscle in contrast to collagen.