10X Tris-Borate-EDTA (TBE) (0.9 M Tris-Borate 0.01 M EDTA pH - 4 x 1 L

TBE is often used in procedures involving nucleic acids, the most common being electrophoresis in molecular biology. Tris-acid solutions are effective buffers for slightly basic conditions, which keep DNA deprotonated and soluble in water. EDTA is a chelator of divalent cations, particularly of magnesium (Mg2+). As these ions are necessary co-factors for many enzymes, including contaminant nucleases, the role of the EDTA is to protect the nucleic acids against enzymatic degradation. But since Mg2+ is also a co-factor for many useful DNA-modifying enzymes such as restriction enzymes and DNA polymerases.