Isoelectric Separation

Application ID: 10626


This example applies the Electrophoretic Transport and Laminar Flow interfaces to model isoelectric separation in a free-flow electrophoresis device. A stream containing six different ionic species is shown to be divided into pure component streams by means of migrative transport in an electric field.

Free-flow electrophoresis can separate macromolecules such as proteins, based on their mobility perpendicular to the flow of the carrier fluid. If, in addition, a pH gradient is applied across the carrier flow, then molecules can be focused along their isoelectric points. The isoelectric point is the pH at which the molecule has zero net charge. Molecules with a positive net charge will travel in the direction of the electric field, along the pH gradient, until they reach the isoelectric point. At this instance, the migrative transport is switched off as the molecules net charge is zero. Similarly, anionic species travel in the direction opposite of the electric field.

This model example illustrates applications of this type that would nominally be built using the following products: