Tonsil epithelium is a heterogeneous lymphoid organ containing two different types of actively differentiating epithelia, the lining stratified squamous epithelium and the reticulated crypt, or lymphoepithelium. The tonsil crypts represent a specialized compartment, important in the immunological functions of the tonsil because of the immediate proximity of the epithelial and lymphoid tissues. In situ staining of tonsil epithelium suggests that expression of the simple epithelial keratins K8, K18 and K19 is located to the crypt epithelial cells. Cell culture of tonsil epithelium produces heterogeneous squamous epithelial cells in which differentiation appears to be ongoing and keratin expression patterns are consistent with those found in tonsil epithelial cells in situ. HTEpiC from ScienCell Research Laboratories are isolated from human tonsil. HTEpiC are cryopreserved at passage one and delivered frozen. Each vial contains >5 x 105 cells in 1 ml volume. HTEpiC are characterized by immunofluorescence with antibodies specific to cytokeratin18 and/or cytokeratin-19. HTEpiC are negative for HIV-1, HBV, HCV, mycoplasma, bacteria, yeast, and fungi. HTEpiC are guaranteed to further expand for 15 population doublings under the conditions provided by ScienCell Research Laboratories. Recommended Medium It is recommended to use Tonsil Epithelial Cell Medium (TEpiCM, Cat #2561) for culturing HTEpiC in vitro.