Shown is an immunocytochemical double-label with an antibody against CD31 (red) and the lectin Ulex europaeus
agglutinin-1 (UEA-1, green) of cultured Macaca monkey retinal microvascular cells. CD31 is localized to endothelial cell membranes, especially at intercellular junctions. UEA-1 marks all
nuclei but preferentially labels the cytoplasm of the single pericyte in the field.