Electrophoresis buffer

An electrophoresis buffer (colloquially also running buffer ) is a buffer that is used for electrophoresis .

properties

Electrophoresis buffers are mostly used in gel electrophoresis to separate macromolecules , e.g. B. in biochemistry for the separation of biopolymers such as DNA , RNA or proteins . The gel is placed in the electrophoresis buffer (horizontal gel electrophoresis) or at least in contact with the electrophoresis buffer at both ends (vertical gel electrophoresis). The electrophoresis buffer contains salts with the buffer ions, which are dissociated in aqueous solution and increase the conductivity of the solution or lower the electrical resistance . The ionic strength of the electrophoresis buffer determines the ion mobility , the migration speed and the heating of the gel. The sample buffer added to the samples before electrophoresis and the gel contain the same buffer ions as the electrophoresis buffer.

Proteins

The typical buffer ion pairs that are used in the course of electrophoretic protein purification consist of either TRIS and glycine ( Tris-glycine buffer ), TRIS and tricine, or BisTris and glycine. The methods used for the electrophoretic separation of proteins include SDS-PAGE or native PAGE . Various buffer systems have been developed for native gel electrophoresis .

Nucleic acids

When separating nucleic acids , the electrophoresis buffers used , among others, are TAE buffers , TBE buffers , TPE buffers , sodium borate buffers or lithium borate buffers . The methods used include agarose gel electrophoresis and capillary electrophoresis .

literature

• Friedrich Lottspeich , Joachim W. Engels , Solodkoff Zettlmeier Lay: Bioanalytik . 3rd edition, Spektrum, Heidelberg 2012, ISBN 978-3-8274-0041-3 .
• Cornel Mülhardt: The Experimenter: Molecular Biology / Genomics. Sixth edition. Spectrum Akademischer Verlag, Heidelberg 2008, ISBN 3-8274-2036-9 .
• Hubert Rehm , Thomas Letzel: The Experimenter: Protein Biochemistry / Proteomics . 6th edition, Spektrum Akademischer Verlag, Heidelberg 2009, ISBN 978-3-8274-2312-2 .
• J. Sambrook , T. Maniatis , DW Russel: Molecular cloning: a laboratory manual. 3rd edition, Cold Spring Harbor Laboratory Press, 2001, ISBN 0-87969-577-3 .

Individual evidence

1. ↑ Josie A. Beeley: Gel electrophoresis: Proteins. MJ Dunn, Bios Scientific Publishers, Oxford 1993, pp. 176, 15.00 / US $ 30.00. In: Electrophoresis. 15, 1994, p. 1001, doi : 10.1002 / elps.11501501147 .