Na-dependent amino acid transporters play an essential role in the uphill transport of amino acids across the plasma membrane. In this study, a novel transporter target was used for which few specific pharmacological tools are available. The aim of this study was to establish a secondary screening assay using the direct electrophysiological measurement of the transporter to identify inhibitors. Using the SURFE2R 96SE, substrate specificity was determined and inhibitors could be identified.