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Gel Electrophoresis

  1. Reiner Westermeier

Published Online: 15 FEB 2013

DOI: 10.1002/9780470015902.a0005335.pub2



How to Cite

Westermeier, R. 2013. Gel Electrophoresis. eLS. .

Author Information

  1. Serva Electrophoresis GmbH, Heidelberg, Germany

Publication History

  1. Published Online: 15 FEB 2013


Gel electrophoresis is the core separation technique for genetic analysis and purification of nucleic acid fragments for further studies. In an electric field the negatively charged deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) fragments migrate through a porous gel matrix toward the positive electrode, the anode. Because of the sieving effect of the gel, shorter fragments move faster than larger ones. In this way the DNA or RNA samples are separated according to their molecular sizes into distinct zones, which can be detected by specific visualisation methods. The most frequently used technique is the separation of DNA fragments in agarose gels in simple flatbed boxes combined with the detection of stained bands under ultraviolet light. Polyacrylamide gels are employed, when small fragments have to be analysed or very high resolution down to one single base pair is required. In contrast to capillary electrophoresis the substrate does not need to be prelabelled.

Key Concepts:

  • With gel electrophoresis very high resolution of nucleic acids can be achieved.

  • TBE buffer is the standard buffer for DNA and RNA gel electrophoresis.

  • Agarose electrophoresis is the standard method for DNA restriction fragment analysis and purification of DNA and RNA fragments.

  • Gel electrophoresis is better suitable for preparative applications than capillary electrophoresis.

  • Native polyacrylamide gel electrophoresis of amplified nucleic acid fragments is a simple and rapid method for the detection of single-nucleotide polymorphisms.


  • gel electrophoresis;
  • agarose gel;
  • polyacrylamide gel;
  • genotyping;
  • electrophoretic mobility