Nöding, BerndBerndNödingKöster, SarahSarahKöster2017-09-072017-09-072012-02-22https://resolver.sub.uni-goettingen.de/purl?gro-2/8946Intermediate filaments play a key role in cell mechanics. Apart from their great importance from a biomedical point of view, they also act as a very suitable micrometer-sized model system for semiflexible polymers. We perform a statistical analysis of the thermal fluctuations of individual filaments confined in microchannels. The small channel width and the resulting deflections at the walls give rise to a reduction of the configuration space by about 2 orders of magnitude. This circumstance enables us to precisely measure the intrinsic persistence length of vimentin intermediate filaments and to show that they behave as ideal wormlike chains; we observe that small fluctuations in perpendicular planes decouple. Furthermore, the inclusion of results for confined actin filaments demonstrates that the Odijk confinement regime is valid over at least 1 order of magnitude in persistence length.enjournal_article10.1103/PhysRevLett.108.088101224635760003005760000263142580cytoskeletoncellular biophysicsmicrofluidics