Historical Background
Standard gel electrophoresis techniques for separation of DNA molecules provided huge advantages for molecular biology research. However, it was unable to separate very large molecules of DNA effectively. DNA molecules larger than 15-20kb migrating through a gel will essentially move together in a size-independent manner. At Columbia University in 1984, Schwartz and Cantor developed a variation on the standard protocol by introducing an alternating voltage gradient to improve the resolution of larger molecules. This technique became known as Pulsed Field Gel Electrophoresis (PFGE). The development of PFGE expanded the range of resolution for DNA fragments by as much as 2 orders of magnitude.
Read more about this topic: Pulsed Field Gel Electrophoresis
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