The reaction of potassium ferrocyanide with ferric iron to yield a dark blue precipitate at the sites of the ferric iron. Used to determine ferric iron in tissues, particularly in the diagnosis of disorders of iron metabolism.

Synonyms: Prussian Blue Reactions, Reaction, Prussian Blue, Reactions, Prussian Blue, Reaction, Ferrocyanide, Blue Reaction, Prussian, Prussian Blue Reaction, Ferrocyanide Reactions, Blue Reactions, Prussian, Reactions, Ferrocyanide, Ferrocyanide Reaction