Home > Biological Detection > Technology > Electrophoresis > Pulsed-Field Gel Electrophoresis (PFGE)

Pulsed Field Gel Electrophoresis addresses the limitations of conventional gel electrophoresis to separate large fragments of DNA that are not adequately separated using standard gel electrophoresis. DNA is first treated with restriction enzymes to specifically break the DNA molecule into individual pieces. The digested DNA is placed at one end of the gel. A pulsing electric field applied across the gel drives the DNA pieces into the gel over a period of hours. The procedure for this technique is relatively similar to performing a standard gel electrophoresis except that instead of constantly running the voltage in one direction, the voltage is periodically switched among three directions; one that runs through the central axis of the gel and two that run at an angle of 60 degrees either side. The pulse times are equal for each direction resulting in a net forward migration of the DNA. PFGE takes longer than standard gel electrophoresis due to the size of the fragments being resolved and the fact that the DNA does not move in a straight line through the gel. The smallest pieces slip through the pores of the gel more quickly, resulting in separated, distinct bands in the gel, based on size.