Iron Stain (Prussian Blue Stain)

Small amounts of ferric iron are found normally in the spleen and bone marrow. Excessive amounts are present in hemochromatosis and hemosiderosis. Prussian blue reaction involves the treatment of sections with acid solutions of ferrocyanides. Any ferric ion (+3) present in the tissue combines with the ferrocyanide and results in the formation of a bright blue pigment called Prussian blue, or ferric ferrocyanide. This is one of the most sensitive histochemical tests and will demonstrate even single granules of iron in blood cells.

Fixation: 10% Formalin.

Sections: Paraffin sections at 5 um.

Result:
Iron (ferric form): bright blue
Nuclei: red
Cytoplasm: pink