Movie 2.

iNeutrophil motility to a gradient of fMLP. Representative time-lapse imaging of WT vs ARPC1B KO iNeutrophils, corresponding to Figure 2. Cells are migrating on 10 μg/mL fibronectin toward fMLP gradients (1 μM) in a microfluidic device, originating at the bottom of the frames. The frame rate is 10 frames per second. Images were acquired every 30 seconds for 45 minutes and movies were trimmed to start 15 minutes after the chemoattractant was loaded. Cells were labeled with Calcein AM. Scale bar is 100 μm.