Numerical simulation of protein separation by continuous-flow electrophoresis

Continuous-flow electrophoresis is a process for separating protein mixtures on a preparative scale. Its resolution is determined by the migration distance at the collection plane and by the fineness of the filament occupied by each protein species. Filaments undergo spreading due to a number of different phenomena, among which electrokinetics and electrohydrodynamics are known to be important. In the first of these, differences in migration velocity between the ionic species give rise to local variations in pH and electrical conductivity near the protein filament. In the second, the local change in electrical conductivity distorts the electric field, thus inducing shear stress in the liquid and creating a local flow pattern. A numerical model has been developed to describe these phenomena when two proteins are being separated.