SIMULATION OF 1D AND 2D ELECTROPHORETIC SEPARATIONS IN MICROFLUIDICS CHIPS

PABLO A. KLER; FABIO A. GUARNIERI; CLAUDIO L.A. BERLI

Tandil, Bs. As., Argentina

Congreso; XVIII Congreso sobre métodos numéricos y sus aplicaciones; 2009

Asociación Argentina de Mecánica Computacional

Abstract. Electrophoretic separations comprise a group of analytical techniques such as capillary zoneelectrophoresis (CZE), isoelectric focusing (IEF), isotachophoresis (ITP) and free flow electrophoresis(FFE). In all cases, separation is based on the dissimilar mobility of ionic species under the action of anexternal electric field. These techniques, which are widely used in chemical and biochemical analysis,have been miniaturized in the last years and now represent one of the most important applications ofthe lab-on-a-chip technology. In a previous work, a generalized numerical model of electrophoresis onmicrofluidic devices was presented. The model is based on the set of equations that governs electricalphenomena (Poisson equation), fluid dynamics (Navier-Stokes equations), mass transport (Nerst-Planckequation) and chemical reactions. Also the relationship between the buffer characteristics (ionic strength,pH) and surface potential of channel walls is taken into consideration. In this work, three applicationexamples are presented: (a) an IEF assay with immobilized pH gradient (IPG) including the influenceof electro-osmotic flow on its performance, (b) an IEF assay involving ampholyte-based pH gradient,and (c) a 2D electrophoresis, involving FFIEF plus CZE. The numerical simulation is carried out byusing PETSc-FEM (Portable Extensible Toolkit for Scientific Computation - Finite Elements Method),in a Python environment developed at CIMEC using high performance parallel computing and solvingtechniques based on domain decomposition methods.