Potassium permanganate 0.5% is a solution used in histology and other scientific applications. Potassium permanganate (KMnO4) is a strong oxidizing agent that can be used in dilute solutions as a staining solution.

In histology, potassium permanganate 0.5% is often used as a component of staining methods based on the oxidation of certain cellular components. One such method is the staining of Argentaffin cells, in which potassium permanganate is used as an oxidizing agent to make the cells visible. In some cases, potassium permanganate can also be used as a bleaching agent to remove previous staining or reduce non-specific staining.