Detection of UCH-L1 expression by pre-embedding immunoelectron microscopy with colloidal gold labeling in diseased glomeruli

The purpose of this report was to study the use of pre-embedding immunoelectron microscopy technique with gold and horseradish peroxidase (HRP) labeling in detecting the expression of ubiquitin C-terminal hydrolase 1 (UCH-L1) of podocytes in glomerulonephritis. The specimens of human IgA nephropathy and lupus nephritis were fixed with paraformaldehyde and lysine-HCl buffer, labeled by colloidal gold or HRP, embedded with epoxy resin, and examined under the transmission electron microscope. The high density of gold particles or peroxidase reaction products (DAB) combined with UCH-L1 was obvious in cytoplasm and processes of podocytes. This modified technique of pre-embedding immunoelectron microscopy could perfectly preserve the ultrastructure of kidney and expose antigens which is valuable for clinical diagnostic work and experimental research.