The ultimate goal of the immunocytochemistry is to get the best signal with the lowest background while preserving ultrastructure. Unfortunaly too often the experimentator faces a compromise between density of the signal and ultrastructure preservation (1). with the advent of hight resolution confocal light microscopy, two photon imaging and other new technologies there is a need to provide the best immunocytochemical complementary results with the high resolution of the electron microscope. But often for exemple the high level of labelling observed by immunofluorescence microscopy is not matched by immunocytochemistry (2). One approach to obtain comparable levels of labelling is to use comparable protocols. We propose here such a new immunogold method. to illustrate our point we used a very convenient biological material, the adherent cells grown on 35 mm plastic culture dishes. The following procedure was applied : Confluent endothelial cells were fixed in situ for 3 hours with the following freshly prepared and filtered solution : 1 % 1-lysine, 4% paraformaldehyde, 0.04% glutaraldehyde, 0.25% sodium metaperiodate in 0.04M sodium cacodylate buffer, pH 7.4.