These are frames from a high- resolution movie of live fluorescence confocal microscopy. The membranes (outlines) of ectoderm and mesoderm cells are labeled in green and orange, respectively. In the first frame, the two types of cells are in tight contact, and their membranes appear merged (green + orange = yellow). In frames 2 and 3, a repulsive reaction is triggered. While cells are being pulled away (arrows), adhesive contacts are ripped apart, leaving behind threads of membranes (arrowhead), just like when one tries to detach two objects that are glued together.