TBE (Tris-Borate-EDTA) Electrophoresis Buffer

TBE is one of the very common electrophoresis buffers, used for agarose gel analysis of DNA. It contains Tris, Boric acid, and EDTA and has pH ≈ 8.3 (cshlp-pdb.rec8458). Tris-borate provides electrical conductivity as well as maintains the pH of the buffer. EDTA does not have any essential function in electrophoresis buffers but it is added to reduce the risk of DNA degradation by metal-dependent nucleases (Brody & Kern, 2004; Sanderson et al., 2014). Therefore, a EDTA-free Tris-borate electrophoresis buffer has also been suggested that can be used to perform electrophoresis at high voltage that results in quick run (reduce run time by up to ≈ 3 fold) and have better resolution of low molecular weight DNA fragments (Sanderson et al., 2014).

Pros

• High buffering capacity of TBE makes it a better electrophoresis buffer than TAE for extended and repeated electrophoresis.

Cons

• Borate from the TBE buffer is reported to interact with DNA, which may cause problems in the subsequent enzymatic modification of DNA fragments eluted from the gel. In such cases, use of the TBE buffer should be avoided. TAE is a suitable buffer for this purpose.

TBE buffer can be prepared as a 5x or 10x concentrated solution (cshlp-pdb.rec8458). A 10x concentrated solution has a tendency to precipitate.