Numerical modeling of transport and accumulation of DNA on electronically active biochips

Transport and accumulation of biomolecules, particularly DNA, in active electronic chips are investigated through numerical modeling and experimental verification. Various geometric and design configurations of electronically active DNA chips are considered. Further, we investigate the effect of electric field distribution on practical design of flow cells and chips. Particular attention is focused on the geometric effects on current and electric field distribution which are well captured by a finite element method-based model. We demonstrate that these geometric effects are observed only in buffers of very low conductivity. We also demonstrate that numerical models which do not include the charge transfer mechanism between electrodes and the buffer solution will fail to predict the reduction of these geometric effects with increased buffer conductivity. The review of the technology is based on computer simulation using a finite element-based computational model and experimental results of electric field distribution, DNA transport and accumulation. Comparison of theoretical results for electrophoretic DNA accumulation with those obtained from experiments and a simple analytical model is presented. (C) 2003 Elsevier Science B.V. All rights reserved.