Prof. Ronald Larson, University of Michigan
February 21, 2013
11:00 AM - 12:00 PM
From Rheology to Biology: The Application of Polymer Hydrodynamics to Problems in Biology
Abstract:
Using Stokeslets, elastic elements, and Langevin dynamics, we develop meso-scale “bead-spring” methods to simulate the dynamics of polymer molecules in flow fields, and the self-propulsion of micron-sized bacterial swimmers. These methods allow us to predict the unraveling of long polymer molecules in shear and extensional flow, and in a droplet drying flow used for creating DNA micro arrays. In extensional flow, the unraveling is dominated by highly out-of-equilibrium “dumbbell” and “fold” configurations that produce a highly heterogeneous population of conformations. In shearing flow, the dynamics are dominated by tumbling of molecular configurations, due to vorticity. The results are successfully compared with experiments using single fluorescently stained DNA molecules, including DNA deposited during drying of a droplet. We apply these methods to study the hydrodynamics of swimming of multi-flagellated bacteria, such as Escherichia coli. Finally, we use microfluidic methods to determine the kinetics of target search of proteins along DNA molecules and the rates of transcription of DNA into RNA.
Date posted
Jun 17, 2019
Date updated
Jun 17, 2019