Dynamic actin is required for the capture of diverse phagocytic targets and is a general requirement for binding by professional phagocytes. (A) Quantitation of the ability of RAW macrophages to bind either C3bi-opsonized sRBCs or unopsonized zymosan after treatment with latrunculin B or vehicle (DMSO) alone. (B) Effect of actin perturbation on the ability of primary bone marrow–derived macrophages to bind IgG-opsonized phagocytic targets. Primary macrophages were isolated from the bone marrow of BALB/c mice. A single experiment where 150 macrophages were counted per condition is shown. (C) Effect of latrunculin B on the capture of IgG-coated latex beads by LPS-stimulated bone marrow–derived dendritic cells. Only cells positive for surface expression of CD11c, as determined by immunofluorescence, were counted. (D) Binding of IgG-opsonized beads to BV2 microglial cells. Where indicated, the cells were treated with PMA (100 nM for 5 min) and/or latrunculin B. A, C, and D show means ± SEM of three independent experiments.