High-throughput ion channel binding assays have been configured for filter binding assays, scintillation proximity assays, and fluorescence polarization assays. Ligand binding assays can detect compounds that compete with ligands for binding to a specific site. Given its low cost and high throughput, binding assays have been developed for many voltage-gated and ligand-gated ion channels. Ligand binding assays require previous information of the target binding sites and the formation of a radioligand which is specific to those binding sites.