New methodology for assessment of the Langerhans cell network

A new procedure is described for staining Langerhans cells (LCs) based on the ability of anti‐S‐100 antibody to stain both epidermal LCs and melanocytes, while L‐Dopa stains only melanocytes. This procedure can be used on paraffin‐embedded skin sections and is therefore advantageous for examination of pathological skin specimens. In order to determine how best to quantitate LCs in skin sections the distribution of LCs has been investigated using an improved method for preparation of epidermal sheets from mouse skin. Epidermal LCs stained for their surface membrane‐bound enzyme adenosine triphosphatase were observed to link with each other via their dendrites, forming a single cell layer which undulates throughout the epidermis. It is therefore proposed that LCs in skin sections should be enumerated per unit length, after identification in paraffin‐embedded sections double stained with anti‐S‐100 antibody and L‐Dopa.