Chinese supplier of Tris bufferFunction, advantages and disadvantages of biological buffer (Pb, Tris, glycine)

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Biological buffer is a kind of solution that can keep the pH value of the solution relatively stable when adding a small amount of acid or alkali. Most cells can only move in a very narrow pH range, and a buffer system is needed to resist the pH change in the process of metabolism. In biochemical research, buffer solution is often used to maintain the pH of the experimental system. Biological buffer has many kinds and wide uses. It is necessary to select the appropriate system according to the practical application.

1. Pb buffer (phosphate buffer)

Phosphate buffer, also known as Pb buffer, is a widely used buffer. Due to the secondary dissociation, the pH range of buffer is wide, and acidic, alkaline and neutral buffers with different pH values can be configured.

Advantages of Pb buffer:

① Easy to prepare into various concentrations;

② Wide range of pH value;

③ PH is less affected by temperature.

Disadvantages of Pb buffer:

① It is easy to precipitate with common calcium, magnesium and heavy metal ions;

② Inhibit some biochemical processes.

2. Tris buffer

Tris buffer is widely used in biochemical research. It is a weak base and is usually used in the "neutral" range.

Advantages of Tris buffer:

① Because Tris base is highly alkaline, this buffer system can be used only 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, so it must be prepared at the use temperature. 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 should be tightly sealed;

④ It interferes with some pH electrodes, so electrodes compatible with tris solution should be used.

3. Glycine buffer

Glycine buffer has a wide range of pH value and wide application range. The pH value ranges from 2.0 to 11.0. The most common systems and pH ranges are shown in the following table: glycine buffer ＾ pH range glycine HCl ＾ 2.0 ~ 5.0 glycine NaOH ＾ 8.0 ~ 11.0 glycine Tris 8.0 ~ 11.0 glycine buffer 7.8 ~ 8.8 glycyl glycine buffer 8.0 ~ 9.0 glycine buffer advantages: provide a closer natural environment for cell components and various extracts. Disadvantages of glycine buffer: similar to phosphate buffer system; Interfere with some biochemical reaction processes, such as metabolic processes.