Current-voltage relationship of hERG (Kv11.1) expressed in HEK293 is shown along with pharmacology of 4 hERG-active compounds. The current-voltage relationships for all 384 wells (top) using perforated patch (Escin) and multi-hole chips (4 holes per well) are shown. In all 384 wells, a hERG-mediated current was observed with peak amplitude >700 pA at -20 mV. Using a pharmacology voltage protocol, experiments were stable lasting over 20 minutes. Concentration response curves for astemizole, pimozide, cisapride and terfenadine revealed IC50 values consistent with those found in the literature.