Electron Microscopy of Melanophagocytosis the Human Skin Window •In TECHNIQUE AND CONFIRMATION OF THE NATURE OF THE PARTICLE

A modification of a tissue culture technique successfully applied to obtain preparations of the inflammatory re-sponse studied by the human skin window technique, is described. Previously described melanin granules in macrophages in Cape Coloured responses could be shown to consist of nests of melanosomes. S. Afr. Med. J., 48, 265 (1974). In a series of earlier papers leucocytic melanin transport was described, and the events in the human skin window detailed.1- ' The human skin window technique offers con-siderable technical problems for electron microscopy, and apart from a casting technique " we are unaware of any electron microscopic observations by this technique. This communication describes our experience with a modification of a tissue culture technique ' for the study of the human skin window preparation. Our main objec-tive was to establish the nature of the granules, cyto-chemically identified as melanin granules. ' Since our earlier studies, this became necessary because a histogenetic re-latiOnship between mast cells, melanocytes and melano-phages was deduced from the morphological, enzymatic, and histochemical evidence of Okun and co-workers."" TECHNIQUE The skin window preparation is obtained by scraping away epidermis from the skin of the sterilised forearm, until minute bleeding points indicate that the corium has been reached. On this surface a drop of egg-white is placed to stimulate the inflammatory reaction against a non-immune antigen. This is covered by a sterile, chemic-aUy clean, glass coverslip, held in place by a sterile card-board disc. The coverslips are removed at suitable inter