Comparison of EB uptake and membrane blebbing in BAECs. BAECs on glass cover-slips were perfused with HBS at 37°C. A phase (left) and fluorescence (right) image pair was obtained every 30 sec for 40 min. MTX (0.3 nM) was added to the bath solution at time 5 min. The montage shows image pairs at the times indicated above each pair. Bleb formation occurs between 8 min and 22 min as shown by the examples indicated by the yellow arrows. Bleb dilation occurs between 22 and 38 min as shown by the examples indicated by the red arrows. The complete time-lapse video is available in the Additional Data Files section (File 1). Ethidium uptake as a function of time was quantified as described in Materials and Methods in defined regions over each cell (colored squares indicated at time 38 min) and plotted as a function of time (lower right panel). Results shown are representative of 19 individual experiments using various concentrations of MTX and different vital dyes.