Advantages and disadvantages of Tris buffer, configuration method and Application

Details:

Tris buffer Chinese name is trimethylolaminomethane; Aminobutanol; Bradykinin; 2-amino-2 - (hydroxymethyl) - 1,3-propanediol is a white crystal or powder. It is soluble in ethanol and water, slightly soluble in ethyl acetate and benzene. It is corrosive and irritating to copper and aluminum.

Tris has high buffer capacity, high solubility in water and is inert to many enzyme reactions, making Tris a very satisfactory buffer for many biochemical purposes. It is generally used to stabilize the pH of the reaction system at pH 7 Strong buffer capacity between 5-9.0.

Advantages of Tris buffer:

① Because Tris base is highly alkaline, only this buffer system can be used to prepare a buffer with a wide range of pH from acidic to alkaline;

② It has little interference with biochemical process and does not precipitate with calcium, magnesium ions and heavy metal ions.

 Disadvantages of Tris buffer:

① The pH value of the buffer is greatly affected by the solution concentration. When the buffer is diluted ten times, the change of pH value is greater than 0.1;

② The temperature effect is large, and the temperature change has a great impact on the pH value of the buffer, △ PKA / ℃ = - 0.031. For example, the pH of the buffer at 4 ℃ is 8.4, then the pH at 37 ℃ is 7.4. Therefore, it must be prepared at the service temperature, and the tris HCl buffer prepared at room temperature cannot be used at 0 ℃ ~ 4 ℃;

③ It is easy to absorb CO2 in the air, so the prepared buffer shall be tightly sealed;

④ This buffer will interfere with some pH electrodes, so electrodes compatible with tris solution should be used.

 Tris buffer preparation method:

There are two methods to prepare Tris HCl buffer: prepare 0.05 mol / L Tris and 0.05 mol / L HCl solution respectively, and then mix them according to the volume listed in the common table. However, dilute hydrochloric acid of standard concentration is not easy to prepare, so another method is often used: take the preparation of 1 l 0.1 mol / L Tris HCl buffer as an example: first weigh 12.11 g Tris base and dissolve it in 950 ml ~ 970 ml deionized water, add 4 N HCl while stirring, measure the pH value of the solution with a pH meter to the required pH value, and then add water to make up to 1 L.

Tris buffer pH range:

Tris buffer is a buffer widely used in biochemical research. Its common effective pH range is in the "neutral" range, such as:

Tris HCl buffer: pH = 7.5 ~ 8.5

Tris phosphate buffer: pH = 5.0 ~ 9.0

Application of Tris buffer solution:

In the electrophoresis buffer, it forms a buffer system with glycine to stabilize the pH value; The Tris-HCl buffer system was used to stabilize the pH value in the gel. It is widely used as a solvent for nucleic acids and proteins; The low ionic strength of Tris buffer can also be used for the formation of intermediate fibers of nematodes; Adding EDTA into Tris hydrochloric acid buffer to make "Te buffer", which can be used for DNA stabilization and storage; Replace the acid solution for pH adjustment with acetic acid to obtain "Tae buffer", and replace with boric acid to obtain tbe buffer. These two buffers are often used in nucleic acid electrophoresis experiments.