Electrophoresis between sieving and reptation: an investigation of the role of shape fluctuations in electrophoresis.
We present numerical simulation results of electrophoretic mobilities of flexible polyelectrolytes over a wide molecular size range moving through gels with various pore sizes. The data are compared to existing models for different molecular size regimes and to experimental results. We observe rather pronounced shape fluctuations of the polyelectrolytes which, especially for larger gel pores or small molecules, have a strong impact on the dynamics of the molecules. Electrophoretic separation, as is used e.g. for DNA sequencing, is best achieved for polyelectrolytes with a radius of gyration of the order of the average pore radius of the gel, i.e. in a molecular size regime where the polyelectrolyte interacts with only a few gel fibers at a given time. A decrease of the gel pore size leads to a systematic decrease of the electrophoretic mobility, but does not lead to a qualitative change in the molecular size dependence, as long as the pore size is larger than the persistence length of the polyelectrolyte.
Völkel
A R
AR
Department of Physics, University of Toronto, Ontario, Canada.
Noolandi
J
J
D004573:Electrolytes; D004586:Electrophoresis / Q000379:methods*; D005782:Gels; D008958:Models, Molecular; D009716:Numerical Analysis, Computer-Assisted; D010316:Particle Size
D004573:Electrolytes; D005782:Gels