A new mode of rotating gel electrophoresis for fractionating linear and circular duplex DNA: the effects of electrophoresis during the gel's rotation.

Linear and circular DNA have been fractionated by use of rotating gel electrophoresis (RGE; RGE is a form of pulsed-field gel [PFG] electrophoresis) in a mode not previously described. This new mode consists of electrophoresis while repeating the following two-step process: rotating the gel by 2 pi radians, followed by holding the gel motionless. With this new mode of RGE: (1) The fractionation by length of linear DNA is greater than that achieved without changing the direction of the field. (2) The simultaneous separation of open circular DNA (48.5-97 Kb) from linear DNA (1-180 Kb) and fractionation by length of open circular DNA is achieved. These latter separations have not previously been achieved by a one-dimensional electrophoresis. The mechanism of linear DNA's sieving in the new mode appears different from that of all previously described procedures of PGF electrophoresis.