Neonatal Human Epidermal Keratinocytes (NHEK) are cultured by first, isolating the keratinocytes from the epidermis of the neonatal skin and then, establishing a primary keratinocyte culture. Upon completion of the primary culture, the cells are harvested, aliquoted into individual vials, and placed in liquid nitrogen storage until shipment. This product has been thoroughly tested and found to be free of the HIV Type I, Viral Hepatitis Type B and C, mycoplasma, bacteria, yeast, and fungi.