Movie 1

3D chemotaxis live imaging of cells migrating in unstimulated controls. Most cells do not move at all, and the cells that do move do not travel much distance and migrate in random directions. Blood was isolated from Botryllus colonies, diluted ½ with filtered seawater, filtered through 10μm cell strainers and mixed with 50% Matrigel. Live imaging was performed on a Leica SP8 confocal microscope at 15s intervals over a time period of 45 minutes. Every particle visible in these movies is a cell, even though many are not within the focal plane.