The outer root sheath (ORS) of the hair follicle surrounds the hair fiber and inner root sheath. It is derived from the epidermis by downward growth. The ORS consists of basal, prickle cells and granular layers near the opening of the follicle onto the skin surface, and modified glycogen-rich prickle cells in the deeper parts of the follicle. The ORS contains several cell populations which play a role in certain functions of the hair follicle, such as serving as a sensory organ and an immunologic sentinel of the skin. A previous study showed that the ORS contains nestinexpressing stem cells, with a variable location of the nestin-expressing stem cells based on the hair cycle. The ORS further represents an alternate source of keratinocytes, which are suitable for skin replacement. HHORSC from ScienCell Research Laboratories are isolated from human scalp. HHORSC are cryopreserved at passage one and delivered frozen. Each vial contains >5 x 105 cells in 1 ml volume. HHORSC are characterized by their mesenchymal cell morphology and immunofluorescence with antibodies specific to fibronectin and/or CD105. HHORSC are negative for HIV-1, HBV, HCV, mycoplasma, bacteria, yeast, and fungi. HHORSC are guaranteed to further expand for 10 population doublings under the conditions provided by ScienCell Research Laboratories. Recommended Medium It is recommended to use Mesenchymal Stem Cell Medium (MSCM, Cat. #7501) for culturing HHORSC in vitro.