The middle ear is composed of three auditory ossicles (incus, malleus, and stapes), the tympanic membrane, and the Eustachian tube. The middle ear functions to transfer acoustic energy from the tympanic membrane to the cochlea. Middle Ear Fibroblasts (MEF), which are located in the middle ear, are mesenchymal cells derived from the embryonic mesoderm. In general, fibroblasts are responsible for extracellular matrix synthesis in connective tissue and play major roles in wound healing. Studies indicate that human MEF may also contribute to pathogenesis of cholesteatoma, or abnormal skin growth in the middle ear, by producing inflammatory factors that result in epithelial cell proliferation. Human MEF (HMEF) are a useful model to elucidate the role of fibroblasts in the development of middle ear cholesteatoma. HMEF from ScienCell Research Laboratories are isolated from human middle ear. HMEF are cryopreserved at passage one and delivered frozen. Each vial contains >5 x 10⁵ cells in 1 ml volume. HMEF are characterized by their spindle morphology and immunofluorescence with antibody specific to fibronectin. HMEF are negative for HIV-1, HBV, HCV, mycoplasma, bacteria, yeast, and fungi. HMEF are guaranteed to further expand for 10 population doublings under the conditions provided by ScienCell Research Laboratories. Recommended Medium It is recommended to use Fibroblast Medium (FM, Cat. #2301) for culturing HMEF in vitro.