Effect of Ca2+ on EB uptake and membrane blebbing in BAECs. BAECs on glass cover-slips were perfused with Ca2+-free HBS at 37°C as indicated in the bottom panel. A phase and fluorescence image pair was obtained every 30 sec for 60 min. MTX (1 nM) was added to the bath solution at time 5 min. Selected phase images are shown at the indicated times (upper panels). The complete time-lapse video is available in the Additional Data Files section (File 4). Ethidium uptake as a function of time was quantified at the single cell level (for 11 cells) as described in the legend to Fig 6 and plotted as a function of time (lower panel). Results shown are representative of 3 individual experiments. For control, identical solution changes were made in the absence of MTX; the image shown (right middle panel) represents the 60 min time point, i.e., 25 min after re-addition of Ca2+ to the bath soluiton in the absence of MTX.