Cell migration paths of MCF10A cells (a human mammary epithelial cell line) were analyzed within a bimodal framework that is a generalization of the run-and-tumble description applied to bacterial migration. The mammalian cell trajectories were segregated into two types of alternating modes, namely, the “directional mode” (mode I, the more persistent mode, and is the analogue of the run phase of bacterial motion) and the re-orientation mode (mode II, the less persistent mode, which is analogous to the tumble phase in bacterial motion). An empirical cut-off value for direction change was used to locate the two modes and find differences between control (MCF10A-pbabe, cells expressing vector only), pre-malignant (MCF10A-neuN, cells expressing normal version of HER-2) and invasive (MCF10A-NeuT, cells expressing tumorigenic version of HER-2) cells. The bimodal analysis was used to determine the turn angle distributions and turn frequencies of these epithelial cells. The influence of pixel size (relative to cell size) and sampling interval (time between images) during data collection on the deduced single cell dynamics of the various cell types was examined. Higher resolution (more pixel information) and smaller sampling intervals were found to give a better estimate of various parameters (such as runtime) and distributions (such as turn-angle distribution) from the bimodal analysis. The persistence time and random motility coefficient value obtained from the analysis of the data with smallest sampling time interval (0.5 min) and highest resolution (1 pixel = 0.163 μm) was found to increase from the control pbabe cells to the invasive neuT cells.