Which pigment can be removed with Lugol iodine during tissue staining?

• A. Mercury pigment
• B. Iron pigment
• C. Carbon pigment
• D. Manganese pigment

Answer: (A)

Lugol's iodine can bleach or dissolve certain metallic pigments, specifically mercurial pigments. It forms iodine–mercury interactions that allow the mercurial pigment to be removed from the tissue section during rinsing, leaving the area clearer. Iron-containing pigments like hemosiderin, carbon pigment, and manganese pigment are not removed by Lugol's iodine under routine staining, so they remain visible. That’s why mercury pigment is the one that can be removed with Lugol's iodine.