Fig. S6.

US-stimulated microbubbles can generate submicrometer pores. (A) Selected maximum intensity projections from a real-time 3D confocal microscopy recording of sonoporation, highlighting the cell membrane (green, first row), PI (red, second row), and preloaded calcein-AM (yellow, third row) channels. Despite no detectable membrane pore and minimal calcein loss, a marked increase in local PI concentration is observed at the site of bubble–cell contact. (B) Quantification of PI and (C) intracellular calcein loss. US: A single, 8-cycle Tukey-windowed pulse at 1 MHz and 300 kPa delivered to a 3-µm-diameter bubble. (Scale bar, 20 µm.)