Some difficulties in research into cell motile activity under isotropic conditions

Movement of Dictyostelium discoideum amoebae under isotropic and anisotropic conditions was recorded and analysed with computer-aided methods and the results are presented ill Various manners as described ill file Subject literature. Cell movement Under isotropic conditions showed great diversity. Some cells moved almost ill a straight path whereas others ill Close Proximity turned around with little net translocation. When cell movement under isotropic conditions was observed, no direct correlation Was found between the total length of cell trajectories and the length of final displacements of the cells. It was necessary to present the results ill the form of histograms, circular diagrams of cell trajectories or ill scatter correlation diagrams showing the motile behaviour of many individual cells. These methods of presentation are more informative than methods which present only average Values, the representative behaviour Of single cells, or start and end points of cell tracks. The latter methods call only illustrate but do not document the results of experiments. The Use of statistical methods appears necessary ill cases when it is difficult to monitor the same cells before and during experimental treatment. However, when cell movement Under anisotropic conditions becomes oriented and ordered as during, tactic cell movements, then the diversity ill cell behaviour decreases and methods based oil estimation of starting and end points of cell positions appear more credible.