We report the first measurements of the intrinsic strain fluctuations of living cells using a recently-developed tracer correlation technique along with a theoretical framework for interpreting such data in heterogeneous media with non-thermal driving. The fluctuations' spatial and temporal correlations indicate that the cytoskeleton can be treated as a course-grained continuum with power-law rheology, driven by a spatially random stress tensor field. Combined with recent cell rheology results, our data imply that intracellular stress fluctuations have a nearly 1/ω2 power spectrum, as expected for a continuum with a slowly evolving internal prestress.
@article{arxiv.cond-mat/0309510,
title = {Microrheology, stress fluctuations and active behavior of living cells},
author = {A. W. C. Lau and B. D. Hoffman and A. Davies and J. C. Crocker and T. C. Lubensky},
journal= {arXiv preprint arXiv:cond-mat/0309510},
year = {2009}
}