Thermal and non-thermal intracellular mechanical fluctuations of living cells

Intracellular stresses generated by molecular motors can actively modify cytoskeletal network, which causes changes in intracellular mechanical properties. We study the out-of-equilibrium microrheology in living cells. This paper reports measurements of the intracellular mechanical properties using passive and optical tweezers-based active microrheology approaches and endogenous organelle particles as probes. Using the fluctuation-dissipation theorem, we compared the two approaches measurements and distinguished thermal and non-thermal fluctuations of mechanical properties in living cells.