6th Annual Symposium
Physics of Cancer
Leipzig, Germany
September 7-9, 2015
Contributed Talk
Characterising single chain motion in a crowded environment
Masoumeh Keshavarz1,2, Hans Engelkamp1, Peter Christianen1, Jan Kees Maan1, Alan Rowan2
1Radboud University, High Field Magnet Laboratory, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
2Radboud University, Faculty of Science, Institute for Molecules and Materials, Huygens building, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
Contact:  | Website
The thermal motion of polymer chains in a crowded environment is anisotropic and highly confined. Whereas theoretical and experimental progress has been made, typically only indirect evidence of polymer dynamics is obtained either from scattering or mechanical response. Towards a complete understanding of the complicated polymer dynamics in crowded media such as biological cells, it is of great importance to unravel the role of heterogeneity and molecular individualism.
Here, we employ extremely stiff synthetic polymers and demonstrate the confined motion of a single chain using time-resolved fluorescence microscopy. This is the first comprehensive study in which we observe the crossover from the Rouse to the reptation regime and quantify the relevant length scales and time constants of polymer dynamics in crowded environments in one experiment at the single chain level confirming de Gennes-Edwards-Doi theory [1-3]. Within our approach, by carefully analyzing the space- and time-dependence of the dynamics of the polymer chains, we have probed the local homogeneity/heterogeneity of the polymer matrix. This local probe technique will allow extracting the same parameters in highly heterogeneous samples that are inaccessible for bulk techniques, especially crowded cytoskeletons in the cell, as a function of the stage of the cell cycle and response to stress.

[1]de Gennes, P. G.Reptation of a Polymer Chain in the Presence of Fixed Obstacles, J. Chem. Phys. , 55, 572-579 (1971)
[2]Doi, M.; Edwards, S. F.The Theory of Polymer Dynamics, Oxford University Press Inc.: New York (1986)
[3]M. Keshavarz, et al.Nanoscale study of polymer dynamics, submitted for publication (2015)
University of Leipzig  |  Faculty of Physics and Earth Sciences  |  Institute of Experimental Physics I  |  Soft Matter Physics Division
© Soft Matter Physics Division, University of Leipzig. Designed and created by sp design. Imprint & Disclaimer