Fig. S1.

Representative force-displacement curve and relaxation curve obtained in the cytoplasm of NRK cells. The semitransparent bars represent SE (n = 20 for A, n = 15 for B). (A) The force-displacement curve is obtained by stretching a 0.5-μm-diameter bead at a speed of 1 μm/s in the cytoplasm. (B) The relaxation curve is obtained by stretching a 0.5-μm-diameter bead to 0.1 μm displacement at a high speed of 30 μm/s in the cytoplasm, then maintaining the location of the bead and recording the force as a function of time. Because the duration of the initial stretching is much shorter than the relaxation time recorded, the loading process can be regarded as instantaneous. The apparent relaxation time τ obtained through exponential fitting of the relaxation curves is 0.79 ± 0.13 s (n = 15, mean ± SD). The orange dashed line is the single term exponential fitting of the relaxation curve.