Anomalous size dependence of the non-linear mobility of DNA

A strong drift velocity non-linearity of the (doublestranded) DNA molecules vs. the electric field was discovered in gel electrophoresis. The non-linear drift velocity of the longer molecules is higher than that of the short ones, depending on the molecular size in a complex fashion. This behavior contrasts with that of the ordinary, linear, drift velocity where short molecules move faster than the long ones. The molecular size dependence of the non-linear velocity or the non-linear mobility has a non-monotonous wave-like character. The non-linear mobility offers possibilities of manipulating the drift velocity at will?the DNA fragments of different size can be made to move in opposite directions in pulsed field gel electrophoresis