Leakage of ANTS/DPX from the vesicles was measured as an increase in fluorescence intensity of ANTS upon addition of the CPP-PMO conjugates (5 mM final concentration) to 2 ml of vesicles (25 mM) (17) . Infinite dilution of the probe used to determine fluorescence of the completely unquenched probe was achieved by solubilizing the membranes with 0.1% (v/v) Triton X-100.