- Histochemical stains confirmed the presence of melanin, since brown pigment removable by permanganate bleaching was demonstrated by Fontana-Masson stain.
- Congo red staining was resistant to permanganate pretreatment.
- Histochemical stains for iron and melanin (Fontana-Masson with and without permanganate bleaching) were also reviewed.
- He had very bad luck with the permanganate bleach and recommends the dichromate bleach instead.
- Each was instructed to wash his hands in a disinfecting permanganate solution.