Dresden 2020 – wissenschaftliches Programm
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BP 10.10: Poster
Montag, 16. März 2020, 17:30–19:30, P2/3OG
Active and passive microrheology for measurement of intracellular mechanics — •Till Münker, Sebastian Hurst, and Timo Betz — Institute of Cell Biology, University of Muenster, Muenster, Germany
Active mechanics that arises from ATP consuming processes like molecular motors or cytoskeletal polymerization have been shown to play an important role for fundamental cellular processes such as proliferation, migration or morphology. However, studies on understanding the more general principles that dictate force generation in this complex structure are missing. Using an optical tweezers based active-passive microrheology approach we determine the viscoelastic shear modulus and the free fluctuations of phagocytosed particles in different cell types. These measurements give access to an effective energy that is indicative for the cellular activity. By comparing the results from different cell types such as epithelial, carcinoma, muscle and immune cells we observe that all cell types follow a similar energy-frequency dependency. We then compared the outcome of these experiments to a simplified model that describes the cytoskeleton as a viscoelastic cage. In our model, we assumed the cytoskeleton to be a soft glassy material which is displaced by a single random force on a distinct timescale. In this approach the functional dependence of the effective energy is determined by the viscoelastic material properties. First experiments confirm this model where a small set of parameters can describe the overall mechanical activity within the cytosol across various cell types.