ELECTROPHORETIC FOCUSING IN A NATURAL STEADY-STATE MOVING PH GRADIENT

The physical and mathematical basis of a natural steady state, moving pH gradient is outlined. With certain approximations, a differential e quation of the concentration of the component contributing to the natu ral steady state, moving pH gradient is formulated. Solutions of the d ifferential equation and the relationships to the resolution calculati ons of both carriers and trace components present in the large excesse s of carriers are presented. The steady state distribution profiles of both amphoteric and nonamphoteric components predict Gaussian distrib utions only if and when the conductivity and the pH gradient remain co nstant within the moving focused zone. The practical significance of t he model is shown by its application to isoelectric focusing (IEF) wit h electrophoretic mobilization, to isotachophoresis (ITP) with polyamp holytic spacers, and to related methods. It is shown that the presente d approximate model represents the transition between classical models of IEF and ITP.