An electrooptical method is disclosed for quantifying the motility response of
cells to external stimuli, wherein a target cell population (formed as a function
of said response) is subsequently optically differentiated by the addition of an
optical differentiation solution, and whereby the targeted cell population becomes
more or less detectable to an electrooptical reading device. The method can be
used to perform chemotactic assays. For such and other purposes, the method can
be performed utilizing high throughput robotic automation.