We describe a set of image processing algorithms for extracting quantitative data from digitized video microscope images of colloidal suspensions. In a typical application, these direct imaging techniques can locate submicron spheres to within 10 nm in the focal plane and 150 nm in depth. Combining information from a sequence of video images into single-particle trajectories makes possible measurements of quantities of fundamental and practical interest such as diffusion coefficients and pair-wise interaction potentials. The measurements we describe in detail combine the outstanding resolution of digital imaging with video-synchronized optical trapping to obtain highly accurate and reproducible results very rapidly.
Crocker and Grier REF developed a set of imaging processing algorithms for their colloidal studies, in which the 3-D locations of individual colloidal spheres can be determined from a single image.
Methods of digital video microscopy for colloidal studies
Journal of Colloid and Interface Science
Chemistry