Toenail. Coloured scanning electron micrograph (SEM) of delamination of a toenail after a fungal infection. Nails are keratinised structures (they contain the protein keratin) made up of dead tissue bound together to form a hard, protective structure on the tips of the fingers and toes. The flattened structures are dead keratinised epithelial cells produced by the mitotic epithelium of the nailbed. It takes about six months for a toenail to grow from base to tip. A similar process occurs in the growth of a hair from its follicle. Magnification: x 200 when printed at 10cm wide.