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Single-molecule observation of anomalous electrohydrodynamic orientation of microtubules.

TitleSingle-molecule observation of anomalous electrohydrodynamic orientation of microtubules.
Publication TypeJournal Article
Year of Publication2008
Authorsvan den Heuvel, MGL, Bondesan, R, Cosentino Lagomarsino, M, Dekker, C
JournalPhys Rev Lett
Date Published2008 Sep 12
KeywordsElectromagnetic Fields, Kinetics, Microscopy, Fluorescence, Microtubules

We use fluorescence microscopy to measure the orientation and shape of microtubules-which serve as a model system for semiflexible rods-that are electrophoretically driven. Surprisingly, a bimodal orientation distribution is observed, with microtubules in either parallel or perpendicular orientations to the electric field. The occupancy of these states varies nonmonotonically with the microtubule length L and the electric field E. We also observe a surprising bending deformation of microtubules. Interestingly, all data collapse onto a universal scaling curve when the average alignment is plotted as a function of B proportional, variantEL3, which reflects the ratio between the driving force and a restoring elastic force. Our results have important implications for the interpretation of electrical birefringence experiments and, more generally, for a better understanding of the electrokinetics of rods.

Alternate JournalPhys. Rev. Lett.
PubMed ID18851339