Prussian Blue Iron Stain Kit (Reaction for Demonstration of Iron), Polysciences

Prussian Blue or Perls’ reaction is used to demonstrate ferric iron and ferritin

This is not a true staining technique, but rather a histochemical reaction. The protein is split off by the hydrochloric acid, allowing the potassium ferrocyanide to combine with the ferric iron. This forms the ferric ferrocyanide or Prussian Blue.