Buffers in gel electrophoresis are used to provide ions that carry a current and to maintain the pH at a relatively constant value. There are a number of buffers used for electrophoresis. The most common being, for nucleic acids Tris/Acetate/EDTA (TAE), Tris/Borate/EDTA (TBE).
Also asked, what is TAE buffer used for?
TAE buffer is a buffer solution containing a mixture of Tris base, acetic acid and EDTA. In molecular biology it is used in agarose electrophoresis typically for the separation of nucleic acids such as DNA and RNA. It is made up of Tris-acetate buffer, usually at pH 8.3, and EDTA, which sequesters divalent cations.
How do you make TBE buffer?
Make a concentrated (5x) stock solution of TBE by weighing 54 g Tris base (FW = 121.14) and 27.5 g boric acid (FW = 61.83) and dissolving both in approximately 900 milliliters of deionized water. Then add 20 milliliters of 0.5 M EDTA (pH 8.0) and adjust the solution to a final volume of 1 liter.
Why do you use a buffer in gel electrophoresis instead of water?
The buffer is needed to maintain the pH of the DNA solution at close to neutral level because if it can become acidic through electrolysis. The electrical currents caused by the electrodes can cause water molecules to dissociate and release H+ ions.