Electrostatic Field Calculations for Electrophoresis Using Surfaces
- PDF / 822,701 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 88 Downloads / 231 Views
1061-MM09-25
Electrostatic Field Calculations for Electrophoresis Using Surfaces Perumal Ramasamy1, Raafat M Elmaghrabi2, and Gary Halada3 1 Materials Science and Engineering, Stony Brook University, 317, Old Engineering Building, SUNY - Stony Brook University, Stony Brook, NY, 11794 - 2275 2 Dept of Physiology & Biophysics, Stony Brook University, T6-170 Health Sciences Center, Stony Brook, NY 11794-8661, Stony Brook, NY, 11794-8661 3 Materials Science and Engineering, Stony Brook University, 308 Engineering Building, Stony Brook, NY 11794-2275, Stony Brook, NY, 11794-2275 ABSTRACT The distribution of electric field in and near the surface of the electrophoretic cell determines the motion of proteins in the buffer and along the surface. This is a complicated problem, influenced by buffer ion concentration, electrode configuration, and surface and substrate conductivities. Steady state calculations approximating the experimental geometry were made for different arrangements of electrodes using MAFIA (Computer Simulation Technologies) program and ESTAT programs. Electric field distributions in both conducting surfaces like ITO (Indium Tin Oxide) (Kevley Technologies), gold and aluminum and non conducting surfaces were studied. In order to measure the EOF of the buffer neutrally charged fluorescent Poly-Styrene beads of 1 µm diameter were included in the buffer and imaged using confocal microscope. It was observed that the electric filed was highly modified by various factors like the conducting nature of the surface, position of the electrodes, salt concentration in the buffer and distance from the separation surface. INTRODUCTION Recent experiments in DNA flat-surface electrophoresis have yielded much success in terms of its use as a separation mechanism. Separation of polymers like DNA and proteins by surface electrophoresis can be faster than conventional gel electrophoresis. Also it is easier to retrieve the polymers by surface electrophoresis experiments unlike gel electrophoresis methods. In conventional gel electrophoresis the distribution of electric fields is uniform unlike in surface electrophoresis. The distribution of electric field in and near the surface of the electrophoretic cell determines the motion of polymer in the buffer and along the surface. This is a complicated problem, influenced by buffer ion concentration, electrode configuration, and surface and substrate conductivities. For this one has to understand the distribution of electric fields in an electrphoretic cells thoroughly before interpreting the results of an electrophoresis experiment (1-9). In this article, we try to study the effects of various factors upon the distribution of electric fields in a home made electrophoretic cell having different surfaces for separation. The charge distribution is governed by the Poisson – Boltzmann equation (10) (1) Where Ψ is the electroosmotic potential, ρe is the charge density and ε is permittivity.
In addition to the calculation of the electrical field distributions in the electrophoretic cell
Data Loading...
