Xenopus laevis oocytes are an expression system that is particularly well suited for the characterization of membrane transporters. Oocytes possess only very little endogenous transport systems and therefore transporters can be studied with a high signal-to-noise ratio. This book chapter provides the basic methods to use Xenopus oocytes for the characterization of transporters by radiotracer experiments. While the methods described here were established to study auxin transport they can easily be adapted to study other hormone transporters and their substrates.
Keywords: Import export; Liquid scintillation; Microinjection; Radiotracer; Transport; Xenopus laevis oocytes.