a(ii)) Scatter plots showing passage length and maximum of the frame to frame instantaneous speed for each single particle (blue), small cluster (green) and large cluster (red). The rectangles represent the major distribution of these particles, containing 79 single particles (blue), 92 small clusters (green) and 75 large clusters (red), respectively. ( a(i)) Histogram showing the distribution of maximum speed of single particles (blue), small clusters (green) and large clusters (red). ( a(iii)) Histogram showing the distribution of passage length of single particles (blue), small clusters (green) and large clusters (red). Data were collected from 100 randomly selected spots in three independent experiments. ( b) Average passage length and ( c) average maximum speed of fPlas-gold (data obtained from single-particle analysis shown in a, and were presented as the mean±s.e.m.). ( d) Average speed ( v) of fPlas-gold in cells. Particles observed using DFM were classified as single particles, small clusters and large clusters while the ones observed using FM were classified as high- and low-mobility ones, respectively. Corresponding curves of MSD are shown in Supplementary Fig. 19. Data were collected from 50 spots in three independent experiments for each group and presented as the mean±s.e.m. * P<0.05, ** P<0.01, according to two-tailed two-sample t-test.