Localization of podoplanin in dermal lymphatic and blood capillaries, using indirect immunogold labeling with affinity purified rabbit anti-podoplanin IgG on ultrathin Lowicryl sections. A: This vessel was identified as lymphatic capillary with overlapping, interdigitating endothelial junctions (J) with desmoses (D), and lack of erythrocytes in the lumen. Podoplanin is distributed on the endothelial surface, with strong preference of the luminal surface. Few gold particles are found on the basolateral surface (arrowheads). B: Dermal blood capillary with an erythrocyte in its lumen, immunolabeled with anti-podoplanin IgG as in A. Gold particles were not found on endothelial cells nor on pericytes and erythrocytes. C: Double-labeling of a dermal lymphatic capillary with anti-podocalyxin IgG (10-nm gold particles, arrowheads), and anti-podoplanin IgG (5-nm gold particles, arrows). Both markers were found on the endothelial surface. MV, microvillus; J, junction; D, desmosome-like structure; Ery, erythrocyte. Magnification, ×40,000.