Modeling and simulation of non linear electrophoresis

Jaesool Shim

doi:10.7273/000005718

This dissertation reports multi-dimensional numerical implementation and analytical solutions of two highly used electrophoretic separation techniques, isoelectric focusing (IEF) and isotachophoresis (ITP), in a microfluidic lab on a chip. A number of proteins and ampholytes have been simulated to elucidate the time evolution behaviors of proteins in microgeometries for the two techniques. Furthermore, a new pK determination method was developed from protein titration curve for computer simulation. As the final subject of the dissertation, the parallel computing model is developed in isoelectric focusing. Numerical modeling and simulation of ampholyte based isoelectric focusing were first developed to demonstrate the effect of complex microgeometries on the protein focusing under the influence of electric fields. A multi-dimensional computation model is formulated based on the mass conservation and ionic dissociation relations of amphoteric macromolecules, charge conservation, and the electroneutrality condition. 2D IEF is performed in the pH range using multiple ampholytes in the planar channel and in the contraction-expansion channel. In addition, for the parametric study, the effects of ampholyte dissociation constants and ampholyte concentration on protein separations are studied in on-chip isoelectric focusing. In isotachophoresis, various advection and diffusion schemes are simulated for optimizing the numerical approach such as upwind, hybrid and power-law scheme. A nondimensional standard deviation index was introduced to evaluate the result of isotachophoresis and a cell Peclet number was suggested for accurate results of isotachophoresis simulation. The isotachophoresis model was specifically developed to expand the capillary (1D) microchannel to multi dimensional microchannel for complex microchip design. In the pK determination method, the new pK determination method was capable of being employed from simple amino acid to complex protein titration curve to determine multiple pK values from titration curve. Finite Volume based parallel implementation was conducted in isoelectric focusing for high speed simulation in the presence of up to 96 numbers of input components which are ampholytes and proteins. The application was conducted on message passing interface (MPI). The parallelism was obtained in two equations (conservation of concentration equation and electroneutrality equation).

Modeling and simulation of non linear electrophoresis

Files and links (1)

Abstract

Metrics

Details