- Distinguishing pigments: haemosiderin stains positive, whereas melanin and lipofuscin do not.
- Identifying asbestos fibres that have become coated with haemosiderin.
- Identifying Michaelis-Gutmann bodies in malakoplakia.
Dilute mineral acid hydrolysis releases ferric ions (Fe3+) bound to protein. Free Fe3+ combines with hexacyanoferrate ions (supplied as K4Fe(CN)6) to form a deep blue, water-insoluble, pigment, potassium ferric ferrocyanide, also known as Prussian Blue. Ferrous ions (Fe2+) does not react in the same way. It is usually then counterstained with a dye such as Neutral Red or Safranin O.
- ↑ Perls M. Nachweis von Eisenoxyl in gewissen Pigmenten. Virchows Archive für Pathogogische Anatomie und für Kilinishche Medizin 1867;39:42-48.