PH 10 Tromethamine Tris Buffer Configuration Method And Application

The advantages and disadvantages of Tris buffer configuration method and application

The Chinese product name of Tris is tris(hydroxymethyl)aminomethane; tromethamine; tromethamine; 2-amino-2-(hydroxymethyl)-1,3-propanediol. It is a white crystal or powder. Soluble in ethanol and water, slightly soluble in ethyl acetate and benzene, corrosive to copper and aluminum, and irritating chemicals.

Tris has a high buffer capacity, high solubility in water, and is inert to many enzymatic reactions, making Tris a very satisfactory buffer for many biochemical purposes. Generally used to stabilize the pH of the reaction system, with a strong buffering capacity between pH 7.5-9.0.

Advantages of Tris buffer:

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

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

Disadvantages of Tris buffer:

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

② The temperature effect is large, and the temperature change has a great influence on the pH value of the buffer solution, △pKa/℃＝-0.031, for example: the pH of the buffer solution at 4℃=8.4, then the pH=7.4 at 37℃, so it must be Prepare at the temperature of use. 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 should be tightly sealed;

④ This buffer has a certain interference effect on some pH electrodes, so an electrode compatible with Tris solution should be used.

Tris buffer configuration method:

There are two ways to prepare Tris-HCl buffer: prepare 0.05 mol/L Tris and 0.05 mol/L HCl solutions respectively, and then mix according to the volumes listed in the common table. However, because standard concentration of dilute hydrochloric acid is not easy to prepare, another method is commonly used: Take the configuration of 1 L 0.1 mol/L Tris-HCl buffer as an example: first weigh 12.11 g Tris base and dissolve in 950 mL～970 mL deionized water , While stirring, add 4 N HCl dropwise, use a pH meter to measure the pH value of the solution to the desired pH value, and then add water to make up to 1 L.

Tris buffer pH range:

Tris buffer is a widely used buffer in biochemical research. Its commonly used 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; uses the Tris-HCl buffer system in the gel to stabilize the pH; it is widely used as a solvent for nucleic acids and proteins; the low ionic strength of Tris buffer can also be used for nematodes Formation of intermediate fibers; add EDTA to Tris hydrochloric acid buffer to make "TE buffer", which can be used for DNA stabilization and storage; change the pH-adjusting acid solution to acetic acid to obtain "TAE buffer", replace it with Boric acid is available as TBE buffer. These two buffers are often used in nucleic acid electrophoresis experiments.