High-throughput liposome characterization. Multipass resistive-pulse sensing has been previously established as a high-throughput technique to characterize nanoparticles. The frequency of particle capture is dependent on the particle concentration in the external solution. At the concentration of liposomes used in this study, ~5 × 10 9 liposomes/mL, a new liposome is characterized approximately every second. The capture of a new liposome follows the loss of the previous liposome, which occurs after a liposome has diffused too far away from the nanopipette orifice to be recaptured. In this study, the complete data set details ~350 liposomes characterized with multipass resistive-pulse sensing and fluorescence imaging in 400 s (data not shown). Liposomes undergo photobleaching during multipassing, which can be seen in the fluorescence-time trace shown in Figure , where the photobleaching trend follows an exponential decay. Multipassed liposomes are identified based on the magnitude of the resistive pulses, but can also be identified based on the decay of their fluorescence signal.