(a) Fluorescence micrographs showing trafficking of fluorescein isothiocyanate–labeled (green) anti-ICAM carriers of various geometries (0.1 and 1 μm spheres, and 0.1 × 1 × 3 μm disks) to Texas red dextran prelabeled lysosomes (red). Lysosomal colocalization is visualized as yellow. Scale bar = 10 μm. (b) Trafficking of anti-ICAM carriers to lysosomes was calculated as percent colocalization of these fluorescent markers determined by microscopy at the indicated time. Data are mean ± SEM (n > 25 cells, two experiments). Low-value error bars are masked by symbols in the graph. *, Compares 1 μm spheres to 0.1 μm particles at any given time point. #, compares 0.1 × 1 × 3 μm disks to 0.1 μm particles at any given time point. * or #, P ≤ 0.05; ** or ##, P ≤ 0.01; *** or ###, P ≤ 0.001, by Student’s t-test. ICAM, intercellular-adhesion molecule 1.