Light and electron microscopic demonstration of extracellular immunoglobulin deposition in renal tissue.

Extracellular immunoglobulin (IgG) deposits were shown by both light and electron microscopy in renal biopsy material using immunogold labelling. After fixation of tissue in 4% paraformaldehyde and embedding in Lowicryl K4M, semithin sections were cut and stained using the immunogold silver stain. The sections were then viewed and areas of interest were noted; ultrathin sections were cut from the same block of tissue, then stained using immunogold. Good localisation was achieved at both optical and ultrastructural levels allowing direct correlation to be made in the same area of tissue.