Super beautiful image of fluorescence staining of epithelial cells. In blue are the nuclei. The green and red are the "cytoskeleton" which are structural proteins that give the cell its shape and enable it to move by rearrangement of the cytoskeleton. In red are "actin" filaments, which direct movement, and in green are "microtubules" which are involved in cell division and intracellular transport.
I'll probably post more images like this because there are just some absolutely astounding pictures of florescence staining - and, yes, these cells are actually glowing, like a firefly.