Ruthenium red staining of rat glomerulus

Summary The irregularity of ruthenium red (RR) staining for electron microscopy may be partly attributable to its poor diffusion through tissue. In this study, ruthenium red was perfused into kidneys of normal and nephrotic rats. A dense endothelial reaction occurred in both arterioles and glomerular capillaries. Dot-like deposits, most prevalent in the lamina rara externa of the basal lamina of the glomerular capillaries, were also present. The deposits appeared with equal frequency in both normal and nephrotic animals, suggesting a similar distribution of acidic glycoprotein residues. The possible significance of these deposits and other applications for the technique are discussed.