Membrane proteins are involved in various cellular processes, and many of them serve as therapeutic targets for human diseases. Conventional (mammalian, insect, microbial) cell lines often fail to produce recombinant membrane proteins in large quantities. Tetragenetics, Inc. has developed TetraExpress™, a protein expression platform that takes advantage of the unique biology of Tetrahymena thermophila, to overcome the historical limitations of current recombinant systems. TetraExpress™ technology was utilized to tackle an extremely challenging task – rapid production of correctly folded and functional mammalian ion channels in Tetrahymena membranes or in purified form. For example, tetrameric (4 x 64 kDa) potassium voltage-gated channel Kv1.3, a therapeutic target implicated in autoimmune disorders, and a 221 kDa sodium voltage-gated channel Nav1.8, a well-validated target for pain treatment, were shown to localize on plasma membrane and in endoplasmic reticulum when expressed in Tetrahymena, with the levels of expression 50-100 fold higher than those observed in commercially available mammalian cell lines. Both ion channels were isolated at >90% purity, with the yield of 0.5-2 mg from a liter of culture, and reconstituted into phospholipids. Correct folding and functionality of human Kv1.3 were confirmed by binding assays with fluorescent ShK toxin and voltage clamp recordings in Xenopus oocytes injected with Kv1.3 proteoliposomes. Ion channel activity of purified Nav1.8 was demonstrated by electrophysiology in giant unilamellar vesicles using a Nanion Port-a-Patch system. Thus, TetraExpress™ represents an attractive platform that can advance a variety of downstream applications including therapeutic antibody discovery, drug screening, and structure-based drug design. In addition, Tetragenetics, Inc. has partnered with the Tetrahymena Stock Center at Cornell University to facilitate the application of TetraExpress™ to basic and translational research in the form of providing academic community with the opportunity to order starting material for purification of membrane, intracellular or secreted proteins.