Turnbull's Blue Stain involves a chemical reaction where ferrous iron (Fe²⁺) is first converted to ferric iron (Fe³⁺) using an oxidizing agent. The ferric iron then reacts with potassium ferricyanide to produce an insoluble blue compound known as Turnbull's Blue, which can be visualized under a microscope. The specific steps include: 1. Treating the tissue with a reducing agent. 2. Oxidizing ferrous iron to ferric iron. 3. Reacting ferric iron with potassium ferricyanide.
