A Novel use of Fluorescence Microscopy in Evaluation of Renal Biopsies

Extract

Light, immuno, and electron microscopy are standard for evaluation of renal biopsies. For light microscopy (LM), special stains including PAS and Jones silver methenamine (JSM) are frequently used to enhance recognition of renal anomalies related to disease. We recently discovered that fluorescence microscopy (FM) extends the usefulness of frozen and paraffin sections stained with hematoxylin and eosin and may presage the findings of immuno and electron microscopy. With UV illumination and reflected light fluorescence excitation, standard histologie sections reveal pathologic glomerular and other renal changes not evident by conventional bright field microscopy and may obviate the need for additional special stains.

For frozen sections, tissues mounted on gum tragacanth were snap frozen in isopentane chilled with liquid nitrogen and cryosectioned at a thickness of 4-6 μm. For paraffin sections, tissues were fixed in neutral buffered 10% formalin or in Hollande’s fixative (3.6% formalin, 40% picric acid, 25% copper acetate, 1.5% acetic acid) and sectioned at 2-4 μm.