A Microfluidic Device for Automated Electrophysiological Measurements on Xenopus Oocytes under Zero Gravity

A non-invasive electrophysiology system for performing rapid measurements on Xenopus laevis oocytes under varying gravity levels is presented. Our novel approach makes the need for inserting microelectrodes into the cytosol unnecessary. Immobilization of the oocyte on top of an orifice is achieved using a slight air overpressure to ensure that the cell is kept in a stable condition even under varying gravity levels. In our present studies, we overexpressed the epithelial sodium channel (ENaC) and the sodium/phosphate cotransporter (NaPi-IIb). Results obtained under laboratory conditions as well as under microgravity and hypergravity demonstrate the system’s robustness and give first indications of ENaC’s susceptibility to changes in gravity.