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BP: Fachverband Biologische Physik
BP 2: Biopolymers and Biomaterials (joint session BP/CPP)
BP 2.4: Talk
Monday, March 23, 2009, 11:45–12:00, ZEU 260
Active and Passive Microrheology Probes Reconstituted Intermediate Filament Networks — •Sarah Köster1,2, Yi-Chia Lin2, Johannes Sutter2, and David Weitz2 — 1Courant Research Centre Physics, University of Göttingen, Germany — 2Department of Physics and School of Engineering and Applied Sciences, Harvard University, Cambridge, USA
Intermediate filaments (IFs) are one of the major filament systems of the eukaryotic cytoskeleton. Their remarkable tensile strength and biochemical heterogeneity distinguishes IFs from microfilaments and microtubules and identifies them as a key component for cell mechanics. Here, we study in vitro reconstituted vimentin networks by active and passive microrheology. By tracking individual beads we are able to characterize both the overall network properties as well as the degree of heterogeneity and the effect of crosslinking ions on the network structure and mechanics. This also provides a measure of the poresize distribution in the network. Active microrheology, using magnetic tweezers, allows us to determine the viscoelastic properties of the network. By exposing the network to several sequential cycles of applied force, we observe changes in the response due to network reorganization.