Cellular architecture of normal human skin imaged by whole mount tissue microscopy. Human skin has a rich network of white blood cells (specifically dendritic cells, T cells and macrophages) which form sheaths around blood vessels. This image was taken less than 20 micrometres beneath the junction that joins the dermal and epidermal layers of the skin (dermo-epidermal junction). At this level, dendritic cells (stained for CD11c; green) form clusters around and between blood capillary loops (stained for CD31; red). The blind-ended tips of initial lymphatic vessels are just visible (stained for LYVE-1; blue) at this level. This normal cellular architecture is grossly disrupted in diseased skin (see related images). Scale bar (white) represents 200 micrometres.