Which stain is specifically used for detecting iron?

Prussian blue is the specific stain used for detecting iron in tissues and cells. This stain works by forming a blue complex with ferric ions (Fe³⁺). When tissues are treated with Prussian blue stain, any iron present—whether in the form of hemosiderin (a storage form of iron) or free iron—will react with the stain, resulting in a distinct blue coloration. This property makes it an invaluable tool in diagnostic pathology, particularly for assessing conditions like hemochromatosis or hemosiderosis, where excess iron accumulation is a critical factor.

Masson's trichrome is primarily utilized for distinguishing between collagen and muscle tissue, while periodic acid-Schiff (PAS) is used to locate polysaccharides and mucosubstances in tissues. Giemsa stain is mainly used for blood films and cytological samples, specifically for classifying different types of cells. Therefore, Prussian blue stands out as the most appropriate option for the specific detection of iron.