Abstract
Epidermal Langerhans cells are most commonly demonstrated by utilizing their adenosine triphosphatase reactivity. Although this is one of the best methods available to the light microscopist, it is a capricious technique which does not always permit optimal demonstration of this ceil population. Prolonged fixation in cacodylate formalin and incubation in 1.32 × 10-3 molar adenosine triphosphatase permits reliable reproduction and good definition of these dendritic cells.