Addressable bio/chem chips include a plurality of isolated test cells, each addressable by at least two electrodes for measuring electrical characteristics of probe/test molecule interactions. In one embodiment, electrodes are located within a channel to allow for four terminal measurement. In another embodiment, electrodes are arranged in rows and columns and interconnected with electrolyte pads used as test sites. In yet another embodiment, electrodes are arranged in cells, with each cell including a counter electrode surrounded encircled by working electrodes.