Scaling of the microrheology of semidilute F-actin solutions

The viscoelasticity of actin networks is probed over an extended range of f requencies using microrheology techniques, where the thermal motion of smal l beads in the network is measured using diffusing-wave spectroscopy. Despi te large sample-to-sample variations, the data exhibit an unexpected scalin g behavior and can all be collapsed onto a single master curve, indicative of a surprising universality in the elastic properties. The scaled data pro vide a precise measure of the average behavior of the actin networks and in dicate that at high frequencies omega, the shear modulus, increases as omeg a(3/4).[S0031-9007(99)08465-3].