This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
Iron in tissues is stained with which of the following stains? 
Select and explain. 
A. Sudan O, B. Prussian Blue, C. PAS, D. None of the above
B: Prussian Blue
Answer: B: Prussian Blue 
Explanation: Iron pigment appears as a coarse, golden, granular pigment lying within the cell's cytoplasm. It can be visualized in tissues by the Prussian blue histochemical reaction, in which colorless potassium ferrocyanide is conveed by iron to blue-black ferric ferrocyanide. Ref: Robbins, 8th edition, Chapter 1.