Fig. 2. Anchoring is not induced by cross-linking of receptors by the bead. (A) Plot of the percentage of beads efficiently attached to transfected cells. In all graphs of this figure, the anti-myc antibody coupled to the bead was diluted with another anti-HA antibody, unable to bind to the tagged receptors, in the given proportions (percentage of anti-myc relative to total amount of antibodies coupled to the bead, as depicted on the x-axis). (B) Plot of the percentage of trajectories displaying anchorage for various dilutions of the anti-myc antibody. (C) Plot of the mean ratio of the diffusion coefficients computed before and after anchorage, for various dilutions of the anti-myc antibody. In all figures, values are given with s.e.m. (D) Plot of the time for anchorage for various dilutions of the anti-myc antibody. Note that only the percentage of beads efficiently coupled to transfected cells is diminishing with dilution of the anti-myc antibody, whereas the percentage of trajectories displaying anchorage, the mean ratio of the diffusion coefficients computed before and after anchorage, and the time of anchorage remain almost constant. This shows that anchorage does not rely on aggregation of receptors by the beads.