High Resolution Optical Tracking to Identify Adhesive Events in Vitro

Glycoproteins serve as ligands on metastatic cancer cells to mediate labile adhesive interactions with the vascular endothelium. The sub-second transience of carbohydrate-protein bonding events poses challenges for quantification of adhesion by optical tracking. We report the development of a simple, shape- based algorithm with novelty in its application to high spatiotemporal resolution tracking. We report positional and morphological signals from the spatial, time, and frequency domains for rigid particles and distensible cells. Error was comparable with previous methods: the resolution-dependent positional precision was 7 nm upon minimization of mechanical noise under experimental conditions.