Leucocyte locomotion: comparison of random and directed paths using a modified time-lapse film analysis

A semi-automated method, using a graphic digitizing tablet, for analysing the the tracks of cells taken from time-lapse film is described and illustrated with sample data. Three film sequences of neutrophil leucocytes moving on protein-coated substrata are analysed, and in one of these the cells are moving in a non-random fashion. The randomness of the tracks is tested by an objective method. Cells in the non-random (directed) sequence move faster and make smaller angled turns. No correlation between step length and turning angle could be shown for the random sequences. The method described here should make it possible to undertake visual analyses of cell locomotion with considerably less effort.