(a) Fluorescence micrographs showing internalized fluorescein isothiocyanate–labeled (green) anti-ICAM/spheres (5 μm diameter) versus anti-ICAM/disks (0.1 × 1 × 3 μm) incubated with tumor necrosis factor-α activated HUVECs at 37 °C for the indicated time. Counterstaining with a Texas red secondary antibody reveals surface-accessible anti-ICAM particles (yellow). Dashed line = cell borders determined from phase-contrast images of cell monolayers. Scale bar = 10 μm. (b) Comparison of internalization kinetics of these anti-ICAM particle formulations, automatically quantified from fluorescence micrographs. Data are mean ± SEM (n ≥ 25 cells, two experiments). *Compares spheres to elliptical disks at any given time point. *, P ≤ 0.05, by Student’s t-test. ICAM, intercellular-adhesion molecule 1.