Term Name:	orcein
Synonyms:	C.I. Natural Red 28
Definition:	A variable mixture of several compounds isolated from lichens, the eight most abundant being alpha-aminoorcein, alpha-hydroxyorcein, beta-aminoorcein, gamma-aminoorcein, beta-hydroxyorcein, gamma-hydroxyorcein, beta-aminoorceimine and beta-aminoorceimine (all are phenoxazine-based). It is used for the demonstration of elastic fibres as well as to stain the rough endoplasmic reticulum of hepatitis B infected liver cells.
Ontology:	ChEBI [CHEBI:90299]  ( EBI )