SPT reveals complex VIF motility. (A) Frequency distribution of maximum displacements for full-length trajectories shown in Fig. 2 B. (B and C) Color-coded trajectories and accompanying plots of alpha values computed from 20-frame sliding window MSD analyses centered at the indicated frames. (B) Trajectory that undergoes clear motility state transitions. (C) Highly confined trajectory that remains subdiffusive for the entire trajectory. (D) Frequency distribution with the kernel density estimate of raw trajectory lengths from the cell shown in Fig. 2 B. (E) Standardized 30-frame SPT trajectories of vimentin-SunTag spots in a single RPE cell over 1 min. Trajectories have been color-coded based on maximum displacement according to the legend. (F) Percentage of standardized vimentin-SunTag trajectories classified as motile (red) or immotile (blue) over consecutive, nonoverlapping 5-s bins from a 1-min movie. X axis numbering indicates bin start times. (G–I) Kernel density estimate plots indicating distribution of maximum track speeds (G), mean track directional change (H), and directionality ratio (I) for motile (blue) and immotile (red) standardized trajectories.