Immunogold light and electron microscopic detection of amyloid plaques in transmissible spongiform encephalopathies.

The antigenicity of the 'prion' protein amyloid fibrils was shown to be preserved after glutaraldehyde/OsO4 fixation in uranyl acetate-stained brain tissue blocks from patients with Gerstmann-Sträussler syndrome (GSS) and from mice infected with Creutzfeldt-Jakob disease (CJD). Amyloid plaques were demonstrated by light microscopy in immunogold silver-intensified semithin sections. Under the electron microscope, the amyloid fibrils were labelled in immunogold-reacted ultrathin sections using an antiserum prepared against GSS amyloid plaque cores and mouse amyloid fibrils respectively. The influence of various oxidizing agents (hydrogen peroxide, sodium metaperiodate) on the tissue preservation and the immunohistochemical detection was tested.