The small airways are located at the interface between alveoli and conducting airways. Airway epithelial cells form a continuous lining in the airways and play a unique role as a protective physical and functional barrier to external deleterious agents. Small airway epithelial cells (SAEpiC) regulate the immune responses by contributing to host defense through chemokine production and adhesion molecule expression. They also produce liquids contributing to pulmonary fluid balance. Many airway diseases, such as asthma, bronchiolitis, chronic obstructive pulmonary disease, and cystic fibrosis, involve damage to the airway surface epithelium. The study of human SAEpiC may help to identify new therapeutic options for preventing airway disorders. HPSAEpiC-a from ScienCell Research Laboratories are isolated from human adult lung tissue. HPSAEpiC-a are cryopreserved at passage one and delivered frozen. Each vial contains >5 x 105 cells in 1 ml volume. HPSAEpiC-a are characterized by immunofluorescence with antibodies specific to cytokeratin-18 and/or cytokeratin-19. HPSAEpiC-a are negative for HIV-1, HBV, HCV, mycoplasma, bacteria, yeast and fungi. HPSAEpiC-a are guaranteed to further expand for 15 population doublings under the conditions provided by ScienCell Research Laboratories. Recommended Medium It is recommended to use Small Airway Epithelial Cell Medium (SAEpiCM, Cat. #3231) for culturing HPSAEpiC-a in vitro.