Light micrograph of the epidermis (surface layer) of skin. The normal skin surface pokes up and down forming the so-called rete ridges, forming as the 'spiky' structure in seen in this picture. Layers of the epidermis include the spinous layer (lowermost) which has the maturing pink keratinocytes (skin cells), the corneal layer (uppermost) which is composed of acellular pink and purple keratin material, and the lucidum layer in between the spinous and corneal layers, which is the clear line seen in the picture. Haematoxylin and eosin stained tissue section. Magnification: 200x when printed at 10cm.