Kinematographische Dokumentation einer amitotischen Zellteilung

Summary Identification of argyrophilic cells, in pancreatic islets of normal rabbits, is accomplished by light and electron microscopy in osmium-fixed plastic-embedded tissues.Fixative, pretreatment and pH of silver nitrate solution were essential for the light microscopic study to reveal argyrophilic cells in osmium-fixed plastic-embedded pancreatic islet tissue. The best result was obtained with Dalton's osmium fixation and buffered silver nitrate methanamine solution at pH 9.O. The cytoplasmic granules of argyrophilic cells generally are densely packed but some of the cells show only sparse silver impregnated granules in the cytoplasm. Occasionally there are some non-argyrophilic granular cells in which, after silver impregnation, the cytoplasm appears clear. There are three kinds of cells in the pancreatic islets, i.e., argyrophilic granular cells, non-argyrophilic granular (clear) cells, and beta cells (situated centrally in the islet and stained light yellow in silver impregnated sections).The cells known as argyrophilic cells in light microscopy can be identified as alpha cells in electron micrographs by comparison of consecutive sections of the same cell.The author would like to express his appreciation to professor Roy C. Swan for his generous guidance.