Fig. 5. Viscoelastic properties of the intranuclear region and the cytoplasm. (A) Mean frequency-dependent elastic [G'()] and viscous [G''()] moduli of the intranuclear region (black lines) and cytoplasm (red lines). Open symbols: G'; closed symbols: G''. (Inset) Frequency-dependent phase-angle for cytoplasm (black line) and intranuclear region (red line), ()=tan^—1[G'' ()/G'()]. Examplary angles for liquids (e.g., glycerol), =90° and elastic solids (e.g. concrete), =0°. Mean moduli G' () and G'' () were calculated from the ensemble-averaged MSD, , as described (Mason et al., 1997). Distribution of (B) elastic and (C) viscous moduli, G' and G'', respectively, in the intranuclear region measured at a frequency of 1 Hz. (D) Distribution of shear viscosity _s [which is approximately the product of the plateau modulus G'_p (inset in B)] and the relaxation time _R (inset), _s=G'_pR (see text for details). For panels B-D, n=84; 1 Poise (P) = 1 Pascal second (Pa.s); 1 dyn/cm² = 0.1 Pa = 0.1 N/m².