PatchXpress® Plus is a current-clamp upgrade kit for the PatchXpress 7000A automated patch clamp system. The kit enables analysis of cardiac and neuronal cell excitability through measurement of action potentials. PatchXpress Plus helps ion channel safety labs perform automated action potential prolongation assays to test the effects of candidate ion channel drugs on action potential shape, duration, or burst activity in excitable cells such as pluripotent stem-cell derived cardiomyocytes. The effects of candidate drugs can also be tested on action potential burst firing in neurons or on resting membrane potentials in excitable or nonexcitable cells.