Pulsed field gel electrophoresis

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Pulsed-field gel electrophoresis (PFGE) or just pulsed-field electrophoresis is a method for determining the length of DNA pieces of chromosomal size, e.g. B. to determine the genetic fingerprint or to type bacterial genomes and thus to identify pathogens .

principle

The difference to normal agarose gel electrophoresis is that no temporally homogeneous field is applied, but the polarity is reversed periodically for a short time . With normal gel electrophoresis, large strands of DNA (approx. 30–50 kbp ) migrate at about the same speed, regardless of their size or chain length. The resolution in this area can be considerably improved by reversing the polarity. The theoretical basics have not been researched in detail, but this process makes the greater "inertia" of the larger pieces its own, which can only slowly adapt and realign to the changing field. The different strands "get caught" in the struts of the gel, the shorter strands loosen due to the short polarity reversal phases, and there is not enough time for the longer ones. On average, you accelerate relatively shorter strands compared to the longer ones. For short pieces, the method has no advantages over agarose gel electrophoresis or capillary electrophoresis .

literature

  • Margit Burmeister, Levy Ulanovsky (Eds.): Pulsed-field Gel Electrophoresis. Protocols, Methods and Theories (= Methods in Molecular Biology. Vol. 12). Humana Press, Totowa NJ 1992, ISBN 0-89603-229-9 .
  • Joseph Sambrook , David W. Russel: Molecular cloning. a laboratory manual. 3 volumes. 3rd edition. Cold Spring Harbor Laboratory Press, Cold Spring Harbor NY 2001, ISBN 0-8796-9577-3 .
  • Cornel Mülhardt: The Experimenter : Molecular Biology / Genomics. 6th edition. Spectrum, Akademischer Verlag, Heidelberg 2009, ISBN 978-3-8274-2036-7 .