Understanding Collaborative Effects between the Polymer Gel Structure and the Applied Electrical Field in Gel Electrophoresis Separation

The collaborative effects between an applied orthogonal electrical field and the internal structure of polymer gels in gel electrophoresis is studied by using microscopic-based electrophoretic transport models that then are upscaled via the format of electro kinetics-hydrodynamics (EKHD). The interplay of the electrical field and internal gel morphology could impact the separation of biomolecules that, because of similar chemical properties, are usually difficult to separate. In this study, we focus on an irregular pore geometry of the polymer-gel structure by using an axially varying pore (i.e., an axially divergent section) and an orthogonal (to the main flow of solutes) applied electrical field. The microscopic-based conservation of species equation is formulated for the standard case of electrophoresis of charged particles within a geometrical domain, i.e., a pore, and upscaled to obtain macroscopic-based diffusion and mobility coefficients. These coefficients are then used in the calculation of the optimal time of separation to study the effect of the varying parameters of the pore structure under different values of the electrical field. The results are qualitatively consistent with those reported, in the literature, by using computational-based approaches as well as with experiments also reported in the literature, previously. The study shows the important collaborative effects between the applied electrical field and the internal geometry of the polymer gels that could lead to improving biomolecule separation in gel electrophoresis.