Use of Nanogold Followed by Silver Enhancement and Gold Toning for Preembedding Immunolocalization in Osmium-fixed, Epon-embedded Tissues

A reliable, sensitive, high-resolution method with good structural visualization for preembedding immunoelectron microscopy was proposed. The present technique involves the following processes. Immunolabeling of cryostat sections with primary antibodies and with nanogolds, silver intensification for visualization of nanogold secondary antibodies, gold-toning for stabilization of silver shells, and osmium postfixation and embedding in Epon for good structural visualization. The technique was applied to rat testis with anti-laminln and anti-fibronectin antibodies, showing that these two proteins are localized differentially in the lamina propria of the tissue. Key words: nanogold, silver-intensification, gold toning fibronectin, laminin, testis Immunoelectron microscopy is a versatile technique for investigating detailed localization of various substances. Diverse methods have been devised to apply this technique for reliable high resolution localization studies. Although most of these techniques have inherent limitations, each has its own usefulness