Confocal time sequence of migration arrest. Single HT1080/dual-color cell expressing cytoplasmic DsRed2 (red) and nuclear histone-2B (H2B)–coupled EGFP (green) in rat tail collagen (1.7 mg/ml), in the presence of GM6001. White arrow highlights short-lived repeated prolapses of the nucleus in direction of the leading pseudopod. Imaging at 37°C by laser scanning confocal microscopy (510; Carl Zeiss) and maximum intensity projection of confocal z-stacks with 2.5-min time interval for 100 min.
