Tris base, with the chemical formula C4H11NO3 and CAS number 77-86-1, is a buffering agent commonly used in biochemical and molecular biology experiments. It is particularly important in nucleic acid electrophoresis experiments, which are key steps in DNA separation, purification, and PCR amplification experiments. Therefore, the Tris buffer series is widely used in DNA and RNA related research. Let's talk about two common electrophoresis buffers prepared by Tris - TAE (Tris Acetic Acid EDTA) and TBE (Tris Boric Acid EDTA).

 

The basic principle of Tris preparation of electrophoresis buffer

 

Tris buffer is an alkaline aqueous solution with a pH ranging from neutral to weakly alkaline. In order to make it suitable for electrophoresis experiments, it is usually necessary to adjust the pH value with acid. In nucleic acid electrophoresis, acetic acid and boric acid are commonly used to prepare TAE and TBE buffer solutions, respectively.

 

TAE buffer

 

TAE buffer solution

 

TAE buffer is composed of Tris, acetic acid, and EDTA (ethylenediaminetetraacetic acid). Common formulas include 40mM Tris, 20mM acetic acid, and 1mM EDTA. TAE buffer is suitable for most DNA electrophoresis experiments, especially those that need to recover DNA fragments from agarose gel. The low conductivity of TAE makes it less likely for the electrophoresis tank to overheat during electrophoresis at lower voltages, making it suitable for long-term electrophoresis.

 

TBE buffer solution

 

TBE buffer is composed of Tris, boric acid, and EDTA. The formula is usually 89mM Tris, 89mM boric acid, and 2mM EDTA. TBE buffer is suitable for separating smaller DNA fragments, as the migration speed of small fragments is faster in TBE. The high conductivity of TBE enables it to maintain high resolution during electrophoresis at high voltage, but it can also easily cause overheating of the electrophoresis chamber. Therefore, TBE buffer is often used for short-term electrophoresis experiments that require high resolution.

 

The difference between TAE and TBE electrophoresis buffer

 

1. Applicability of DNA fragment size: TAE buffer is suitable for separating DNA fragments larger than 2kb. In 0.8% agarose gel, the migration rate in TAE was about 10% faster than that in TBE. Therefore, for experiments that require rapid separation of large DNA fragments, TAE is a better choice.

 

2. DNA fragment recovery: Due to the small impact of the components in TAE buffer on subsequent enzyme digestion and amplification reactions, it is suitable for experiments that require DNA fragment recovery after electrophoresis. The boric acid in TBE buffer is an enzyme inhibitor and is not suitable for subsequent experiments that require enzyme cleavage reactions.

 

3. Conductivity and electrophoresis time: TAE has low conductivity and is suitable for long-term electrophoresis without causing overheating of the electrophoresis tank. The conductivity of TBE is relatively high, making it suitable for high-resolution electrophoresis experiments in a short period of time, but prolonged electrophoresis may lead to overheating.

 

4. Resolution and migration speed: For supercoiled DNA, TAE has a higher resolution than TBE, making it more suitable for experiments that require high resolution. TBE has a better effect on separating smaller fragments of DNA. When TBE buffer is used on 2% agarose gel, the migration speed of DNA fragments less than 300 bp is faster.

 

Application of TAE and TBE buffer in electrophoresis

 

TAE buffer solution:

 

1. Large fragment DNA separation: suitable for separating DNA fragments larger than 2kb. Due to its lower conductivity, it can undergo long-term electrophoresis at lower voltages to avoid overheating issues.

 

2. DNA recovery experiment: It is applicable to experiments that need to recover DNA fragments from agarose gel. The components in TAE have a relatively small impact on subsequent enzyme digestion and PCR reactions.

 

3. High resolution separation of supercoiled DNA: TAE provides higher resolution for supercoiled DNA and is suitable for experiments that require detailed analysis of DNA structure.

 

TBE buffer solution:

 

1. Small fragment DNA separation: suitable for separating DNA fragments smaller than 300bp. In high concentration agarose gel (such as 2%), TBE can provide faster migration speed and higher resolution.

 

2. Short term high-resolution electrophoresis: suitable for experiments that require high-resolution electrophoresis in a short period of time. The high conductivity of TBE allows for electrophoresis at high voltage, but caution should be taken to prevent overheating.

 

3. Application in restriction enzyme digestion reaction: Although boric acid in TBE is an enzyme inhibitor, in some experiments, TBE is still used for electrophoresis before restriction enzyme digestion reaction to ensure high-resolution separation.

 

Product packaging

 

Tris is widely used in nucleic acid electrophoresis, and its prepared TAE and TBE buffers have their own advantages and disadvantages, suitable for different experimental needs. When selecting a buffer solution, TAE or TBE should be chosen reasonably based on the specific requirements and objectives of the experiment. As a manufacturer of biological buffering agents, Desheng can supply Tris and TAE raw materials that are inexpensive and have a uniform appearance powder. They are easy to prepare, fast to use, and have stable performance in electrophoresis experiments. If you have any relevant intentions, please click on the website to inquire about details and purchase!