Principle of Prussian blue stain:: (A) Ferrous to ferricyanide, (B) Ferrocyanide to ferroferric cyanide, (C) Ferroferriccyanide to ferrocyanide, (D) Ferrocyanide to ferricferrocyanide
Answer is B. Ans. (b) Ferrocyanide to ferroferric cyanide(Ref: Dacie and Lewis Practical Haematology 11th ed, pg 338)Hemosiderin reacts with potassium ferrocyanide to form a blue compound, ferri ferrocyanide; this reaction is the basis of a positive Prussian-blue (Perls') reaction.