Perls Prussian blue

In histology, histopathology, and clinical pathology, Perls Prussian blue is a commonly used method to detect the presence of iron in tissue or cell samples.

[2] The method does not involve the application of a dye but rather causes the pigment Prussian blue to form directly within the tissue.

[7] Perls did not publish a detailed procedure other than indicating a dilute potassium ferrocyanide solution was applied to the tissue followed by hydrochloric acid.

[9] Many methods of performing Perls Prussian blue stain for iron have been published, [2] Drury and Wallington (1980) give a protocol that uses a mixture of 1 part 2% hydrochloric acid and 1 part 2% potassium ferrocyanide that is applied to the section for 20–30 minutes followed by a rinse in distilled water and application of a counterstain such as eosin, safranin or neutral red.

[5] Potassium ferrocyanide in the staining solution combines with the ferric iron forming the Prussian blue pigment.

Cerebrospinal fluid specimen stained with Perls Prussian blue showing iron containing macrophage (stained blue) surrounded by erythrocytes (stained red)
Section of liver stained with Perls Prussian blue, showing iron accumulations (blue) consistent with homozygous genetic hemochromatosis
Perls Prussian blue components: potassium ferrocyanide and hydrochloric acid .
Perls Prussian blue stained section of liver biopsy showing hemosiderosis