In the skin, melanocytes are situated on the basal layer which separates dermis and epidermis. One melanocyte is surrounded by approximately 36 keratinocytes. Together, they form the so-called epidermal melanin unit. The melanin produced and stored inside the melanocyte in the melanosomal compartment is transported via dendrites to the overlaying keratinocytes. The melanin pigment is a polymer produced inside the melanosomes and synthesised from the amino acid l-tyrosine that is converted by the enzyme tyrosinase to dopaquinone