TAE and TBE Running Buffers Recipe & Video

What are Tris Acetate EDTA and Tris Borate EDTA?

Tris acetate EDTA (TAE) and tris borate EDTA (TBE) are the two most common running buffers used in nucleic acid electrophoresis. As buffers, they have a fairly constant pH and are able to conduct electricity because of their concentration of hydrogen ions. These properties are necessary for gel electrophoresis during which proteins are separated by electric charge.

Preparing Running Buffers

TBE and TAE are most often mixed from their constituent parts into laboratory stock solutions. Both buffers can be purchased at the working concentration or in a powdered or concentrated format that is simply prepared via dilution.

Refer to the recipes below to prepare TAE and TBE in common stock solution concentrations. Our buffer calculator can also help you find the correct dilution (or conversion) for various buffers from stock solution to a desired molarity and volume.

Video: TAE and TBE Buffers for Gel Electrophoresis

Review common TAE and TBE buffer solution recipes and learn which running buffer to choose for your nucleic acid gel electrophoresis application. Research technology specialist Chris Lemke mixes up stock solutions and provides helpful buffer selection tips.

This video was built in collaboration with Seeding Labs, a nonprofit that connects universities and research institutes in developing countries with high-quality surplus lab equipment, training, and professional exchanges.

TAE Buffer 50x Stock Recipe

• 242 g tris base in double-distilled H₂O
  
• 57.1 ml glacial acetic acid
• 100 ml 0.5 M EDTA solution (pH 8.0)

Adjust volume to 1 L.

10x TAE Recipe

For 1L of 10x solution,

• 48.5 g tris
• 11.4 mL glacial acetic acid
• 20 mL 0.5M EDTA (pH 8.0)

1x TAE Recipe

Dilute 1:10

• 0.4 M tris acetate (pH approximately 8.3)
  
• 0.01 M EDTA

using ultrapure water.

TBE Buffer 10x Stock Recipe

• 108 g tris base
• 55 g boric acid
• 900 ml double-distilled H₂O
• 40 ml 0.5 M EDTA solution (pH 8.0)

Adjust volume to 1 L.

1x TBE Preparation

Dilute 10x concentrated TBE buffer 10-fold with ultrapure water.

The final solution should contain:

• 0.13 M tris (pH 7.6)
• 45 mM boric acid
• 2.5 mM EDTA

Buffer Prep Tips

• If precipitation is present, warm to 37 °C and mix until completely dissolved prior to dilution.
  
• It is recommended 1x working solutions be filtered through a 0.2 mm filter before use.
• 1x working solutions can be used until the expiration date on packaging with storage at room temperature. Discard if buffer becomes cloudy or discolored.

Applications

Tris-acetate-EDTA (TAE) running buffer and tris-borate-EDTA (TBE) are commonly used buffers for DNA agarose gel electrophoresis that are especially useful in preparative work.¹

Compared to tris-borate-EDTA (TBE) and tris-phosphate-EDTA (TPE) buffers, double-stranded DNA tends to run faster in TAE. However, because TAE has the lowest buffering capacity of the three buffers, the buffering capacity can become exhausted during extended electrophoresis. Buffer circulation or replacement can remedy this situation.

TAE

The 1x TAE buffer is used both in the agarose gel and as a running buffer. Applied voltages of < 5 V/cm (the distance between the electrodes of the unit) are recommended for maximum resolution.²

TAE buffer has been utilized in agarose gel electrophoresis of RNA.^3,4

A study of free DNA solution mobility in TAE at various buffer concentrations, in the presence and absence of added NaCl, has been reported.⁵

The use of TAE buffer in a denaturing gradient gel electrophoresis method for broad-range mutation analysis has been described.

TBE

TBE buffer is recommended for resolution of RNA and DNA fragments smaller than 1500 bp.

TBE is used with both non-denaturing or denaturing (7 M urea) gels.

It is also routinely used for DNA automated sequencing gel.

Tris-borate-EDTA buffer has been used for pulsed-field gel electrophoresis (PFGE). Applied voltages of less than 5 V/cm are recommended for maximum resolution.

Bionic Buffer is a unique alternative to traditional TBE (tris-borate-EDTA) and TAE (tris-acetate-EDTA) electrophoresis buffers. Bionic Buffer allows for:

• Band resolution in minutes
• Running gels 2-3x faster than in TBE/TAE
• Sharper bands in less time
• Use with pre-cast gels