Primary Normal Human Epidermal Melanocytes (NHEM) are isolated from the epidermis of juvenile foreskin.Melanocytes are located in the stratum basale, but branch out between the keratinocytes in suprabasal layers. About 5-10 % of the cells in the epidermis are melanocytes. The main purpose of melanocytes is the production of melanin, the protein responsible for the pigmentation of the skin, eyes, and hair. Melanin protects the cells in the skin and in deeper layers from the hazardous effects of UV radiation. It is produced and stored in melanosomes, which are located close to the melanocyte membrane, but it can also be transferred to neighboring keratinocytes.PromoCell Normal Human Epidermal Melanocytes are isolated using the PMA (Phorbol Myristate Acetate)-containing Melanocyte Growth Medium. Since PMA is a tumor promoting mitogen, it can interfere with experimental approaches. Therefore, we recommend using cells isolated in Melanocyte Growth Medium M3.