SPTM allows users to track with high precision the diffusion of individual microscopic particles attached to relevant molecules. The information garnered from measurement of particle trajectories provides useful information about the mechanisms and forces that drive and constrain the particles motion. The approach of tracking individual particles has the great advantage of detecting behaviors shown by only a small fraction of the population at any given time. These behaviors could not be seen in measurements of a large population of particles. SPTM also allows the analysis of the lateral mobility of particles confined to small domains. SPTM has proved especially useful in characterizing the motions of small particles on cell surfaces attached to a small number of membrane glycoproteins.

SPT has primarily been used to track the movement of individual plasma membrane components or "molecular motors" with nanometer precision by monitoring the trajectories and rates of movement of the specific component after labeling with antibody-coated submicron colloidal gold particles. For example, recent evidence indicates that the plasma membrane of cells is not one giant ocean with constituents randomly diffusing in two-dimensions, but rather that a substantial fraction of proteins appear confined, at least transiently, to submicroscopic membrane domains. This lateral heterogeneity has important implications for the function of plasma membranes as an interface between the outside world and the inside of cells.