Voltage gradient electrophoresis of nucleic acids on agarose gels

A very simple method is described which allows the separation of DNA molecules in a wide molecular weight range (from 0.6 to about 30 kb) in the same electrophoresis agarose gel. This is based on the achievement of a voltage gradient through a simple device consisting of a Plexiglas plate placed slantwise with respect to the gel surface plane, submerged in the electrophoretic running buffer. Further applications of our system are also described.