The human esophagus is lined by a non-keratinizing, stratified squamous epithelium whose apical cell membranes and intercellular junctional complexes form a barrier against the influx of luminal content. The barrier helps to reduce exposure of surface cells to changes in osmolality, which occurs frequently within the esophageal lumen. Histologically, the esophageal epithelium consists of two zones, the basal and differentiated zones. Cellular proliferation is limited to the basal zone, and the cells are thought to migrate from this area towards the esophageal lumen. Migration is associated with the initiation of differentiation and the sequential expression of differentiation markers. Human esophageal epithelial cells (HEsEpiC) are an excellent in vitro model to study esophageal epithelium physiology and the mechanisms of esophageal carcinogenesis. HEsEpiC from ScienCell Research Laboratories are isolated from the human esophagus. HEsEpiC are cryopreserved at passage one and delivered frozen. Each vial contains >5 x 105 cells in 1 ml volume. HEsEpiC are characterized by immunofluorescence with antibody specific to cytokeratin-18 and/or cytokeratin-19. HEsEpiC are negative for HIV-1, HBV, HCV, mycoplasma, bacteria, yeast and fungi. HEsEpiC can be further cultured under the conditions provided by ScienCell Research Laboratories; however, HEsEpiC are not recommended for expanding or long-term cultures due to limited expansion capacity. Recommended Medium It is recommended to use Epithelial Cell Medium-2 (EpiCM-2, Cat. #4121) for culturing HEsEpiC in vitro.