TAE buffer (50X) ready-to-use solution

TAE buffer is used for nucleic acid electrophoresis on agarose gels under low voltage conditions. Ref.: Loening U.E. (1967) Biochem. J., 102, 251, Ogden R.C. and Adams D.A. (1987) Methods Enzymol., 152, 61.

TAE buffer is the most commonly used running buffer for agarose gels. Originally, this buffer system was developed for polyacrylamide gel electrophoresis with a slightly different composition (40mM Tris; 20mM; NaOAc; 2mM EDTA-Na2; pH7.8). For stabilizing the secondary structure of RNA, sodium acetate was included.

Today, TAE is used in a modified composition (40mM Tris-acetate; 1mM EDTA-Na2; ~pH8.5). TAE has a lower buffering capacity than TBE, but double-stranded, linear DNA migrates
approximately 10% faster through TAE than TBE with the same resolution. The resolution of supercoiled DNA is better in TAE than TBE. Because of its low buffering capacitiy, it may become exhausted during long periods of time at high current. Therefore TAE should be replaced during extended electrophoresis or should be recirculated. An advantage of TAE over TBE is the absence of interactions with agarose, resulting in a higher yield of nucleic acids in preparative agarose gel electrophoresis.

Usually TAE is made up as a 50X concentrated stock solution and employed in an 1X or 0,5X working concentration.