Quantitative assessment of cellular changes provoked by microwave enhanced fixation of parathyroids

Summary Rat parathyroids fixed by microwave enhancement, i.e. microwave irradiation in the presence of glutaraldehyde for 8 s and postfixation with OsO₄ after a delay of 5 min, were compared with parathyroids fixed by perfusion with glutaraldehyde followed by immersion in glutaraldehyde and finally in OsO₄. Morphometric analysis revealed that microwave enhanced fixation led to larger mean cell volume, to larger cell surface area, and to larger suface area in membranes of RER and secretory granules. Though it is not known by which method parathyroid cells are conserved closer to the living state it is obvious that microwave enhanced fixation retains more membranes but provokes centrifugal dislocation of membranes mimiking exocytosis.