Comparison of advantages, disadvantages and applications of HEPES buffer and Tris HCl

Details:

Tris HCl and HEPES are widely used in buffer. Why compare the two of them This is also to let everyone know more relevant information, so as to be more accurate in the process of procurement and use.

1. Tris HCl buffer

Tris buffer is a buffer widely used in biochemical research. It is a weak base, and the commonly used effective pH is in the "neutral" range. Tris HCl buffer: pH = 7.5 ~ 8.5; Tris phosphate buffer: pH = 5.0 ~ 9.0.

1) Tris HCl buffer advantages

The pH buffer in the range from acid to alkali can be configured only with this kind of buffer because of its strong alkalinity; It has little interference with biochemical process and does not precipitate with calcium, magnesium ions and heavy metal ions.

2) disadvantages of Tris HCl buffer

The pH is greatly affected by the concentration, diluted 10 times, and the pH change is greater than 0.1

Large temperature effect, such as pH = 8.4 at 4 ℃ and pH = 7.4 at 37 ℃

2. HEPES buffer

HEPES is a non-ionic amphoteric buffer at pH 7 It has good buffer capacity in the range of 2 ~ 7.4 and is commonly used in biochemical diagnosis kit, DNA / RNA extraction kit and PCR diagnosis kit.

1) HEPES buffer advantages:

In open culture or cell observation, it can maintain a relatively constant pH value and has a harmful effect on cells.

2) Disadvantages of HEPES buffer:

At high concentrations, it may be toxic to some cells and is slightly more expensive than other buffers.

Application of Tris HCl buffer and HEPES buffer

1. Tris HCl buffer

Tris is one of the main components of protein electrophoresis buffer. It forms a buffer system with glycine in the electrophoresis buffer to stabilize the pH in the electrophoresis process. In addition, Tris is also an intermediate for the preparation of surfactants, vulcanization accelerators and some drugs. Tris is also used as a titration standard. As a protein buffer, if mass spectrometry is required for subsequent work, Tris is not suitable to be used and replaced with a buffer that can be tolerated by other mass spectrometers.

2. HEPES buffer

HEPES buffer has a harmful effect on cells. It is a hydrogen ion buffer, which can control the constant pH range for a long time. When used, the concentration is 10-50mmol / L. generally, the buffer capacity can be achieved by containing 20mmol / lhepes in the culture medium. It is also used in environmental, analytical and biological research; As binding buffer and eluent in cation exchange chromatography; As running buffer in gel electrophoresis.