Rapid processing of renal glomeruli for electron microscopy.

Recently we reported a new fine-needle aspiration biopsy method to obtain single glomeruli for electron microscopy in diagnostic and investigative pathology of the kidney. The small size and fragmentary nature of the specimen obtained by this technique necessitated a special device for collecting and processing the tissue for electron microscopy (Pasternack et al., 1978). A new and simpler device has now been constructed, which allows the method to be applied to routine laboratory work and clinical diagnostics. With this new device it is possible to carry out the whole process from fixation to polymerisation of the specimen. Having used conventional processing methods for electron microscopy with the new device, we were tempted to try out previously described rapid processing methods (Estes and Apicella, 1969; Bencosme and Tsutsumi, 1970; Hayatand Giaquinta, 1970; Johannessen, 1973; Rowden and Lewis, 1974) for two reasons. Firstly, the fine-needle aspirate is small enough to guarantee adequate penetration of fixatives, buffers, and embedding materials in a shorter time than is needed when conventional methods are used. Secondly, drainage of the processing fluids allows a thorough exchange of the processing medium. This is thought to render the