New applications of electron microscopy techniques in dermatopathology.

The application of immunostaining techniques to electron microscopy specimens has led to a renewal of interest in electron microscopy in biological research in general, as well as in dermatopathology. Refinements in the preparative procedures have made easier the immunolocalization of antigens both in chemically-fixed and frozen unfixed tissues, embedded in plastic and sectioned. Application of these methods has led to the demonstration of the bullous pemphigoid antigen inside basal keratinocytes. HMB-45 antigen has been found to be present in premelanosomes. Recently, Factor XIIIa has been localized not only in dermal dendrocytes but also in endothelial cells and mast cells.