DA3 cells expressing the fluorescent protein mCherry were grown to 90% confluence in wells of 2 cm diameter in DMEM supplemented with 10% heat-inactivated FCS (Gibco-BRL). A scratch was generated using a 200 µl tip, and the cells were incubated with 80 ng ml-1 Met-Hepatocyte Growth Factor/Scatter Factor (HGF/SF) and subjected to time lapse confocal laser scanning microscopy (CLSM-510, Zeiss, Germany) for approximately 26 hrs, with images taken at 14.5 min intervals. The acquired differential interference contrast (DIC) channel of the time-lapse sequence (shown here) was used for the multi-cellular analysis; the red fluorescence channel was not used here, and is not shown. The analysis used local motion-estimation information to extract spatiotemporal measures for cell acceleration, stretching (strain rate), and directional migration. The coloured strips in the video were extracted from this analysis. These results are under review and a reference to full details will be given upon publication.