Nonlinear focusing of DNA macromolecules

The present paper reports the nonlinear electrophoretic focusing techniques developed after an original idea by Chacron and Slater [Phys. Rev. E 56, 3436 (1997)]. Focusing of DNA molecules is achieved in an alternating nonuniform electric field, created in a wedge gel with hyperbolic boundaries. The fractions separated on such a wedge retained their rectilinear shape during the electrophoresis. Experiments with gel electrophoresis confirm the possibility of a noticeable nonlinear focusing of DNA molecules.