FIG. 3.
Effective creep compliance, Jeff, proportional to the measured MSD, as a function of correlation time, t, in nocodazole. (a) Typical Jeff for three particles at waiting times twait≈0. The represented particles are the same as in Fig. 1. At long times, t, the log-slope α≈1, but this cannot be interpreted as a viscosity because caged diffusion is modified by the ballistic motion of cell crawling. (b) Typical Jeff of three particles, not the same particles as in (a), after twait≈21 min in nocodazole. At long times, the log-slope α≈0, corresponding to caged diffusion and the disappearance of cell crawling. Corresponding trap diameters, calculated as for use in Fig. 2(b), are as follows from top to bottom: 202, 187, and 154 nm, respectively.