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. In this image, T cells (stained for CD3; red) dendritic cells (stained for MHC class II; green) and macrophages (stained for LYVE-1; blue with some cells showing a tinge of green) can be seen. Cell nuclei have been stained with DAPI (grey). This normal cellular architecture is grossly disrupted in diseased skin (see related images). X10 magnification. Scale bar (white) represents 200 micrometres.