Abstract: Multi-well plates having contoured well designs allow multi-stage high throughput parallel assaying of ion channels or ion transporters. A well of a multi-well plate has a bottom region that is sized and shaped to simultaneous accommodate a sensing electrode and a pipette for delivering, e.g., test compounds, wash fluid, and optionally ligands. Such multi-well plates may be coupled with an instrument having a pipette head and an electrode plate. Such arrangement facilitates fluidic contact between cells and fluids provided via a pipette. It also facilitates washing of wells with buffers or other wash solutions to allow serial exposure of test cells to various reagents or other stimuli. Generally, the design allows control and test experiments to be performed on the same cell (or cells) in a single well.