Biological buffers are the most commonly used auxiliary reagents in biochemical testing, and buffers are required for almost all liquid phase reaction systems. Its main function is to maintain the pH value of the reaction system. Commonly used buffers include phosphate, acetate, ammonium salt, and Tris, MOPS, HEPES, etc. in biochemical experiments.
There are many effects of biological buffers on biochemical detection, mainly in the pH value of the solution. The specific effects are illustrated below.
A variety of biological buffers
The effect of buffer on enzyme activity:
Most biochemical tests are reactions involving enzymes. The catalytic efficiency of enzymes is greatly affected by pH and temperature. Each enzyme has its optimal pH value (the pH value at which the enzyme catalytic reaction efficiency is maximum) Therefore, biochemical detection involving enzymes needs to first select a buffer with a suitable buffer range according to the optimum pH value of the enzyme preparation used. Such as Trinder’s reagent enzymatic detection, enzyme-linked immunoassay, etc.
The effect of buffer on the structure of macromolecules:
In addition to the effect of the buffer on the catalytic efficiency of the enzyme, it may also affect the structure of the enzyme. If the pH value of the system and the adaptation pH value of the enzyme are too different, the enzyme may be directly inactivated. On the other hand, even if there is no reaction involving enzymes, buffers are necessary. Many macromolecular substances are often involved in biochemical detection, and their structure is also affected by pH.
For example, acridine ester chemiluminescence detection. Although the reaction of acridine ester and hydrogen peroxide does not require enzyme catalysis, it can emit light directly, but in CLIA analysis, acridinium ester is usually labeled protein, antigen, antibody or nucleic acid, these macromolecular substances The structure is complex and is affected by the pH of the system, so biological buffers are also required.
The effect of buffer on osmotic pressure:
Many buffers are organic weak acid and weak base conjugate acid-base pairs. Different buffers have different ionic strengths, which affect the salt concentration and osmotic pressure of the system. HEPES is often used as a buffer for cell culture, and a buffer that affects the osmotic pressure of the cell membrane and may cause rupture cannot be used.
In addition, different buffers have different complexing capabilities for different metal ions. For example, the system containing calcium and magnesium ions uses Tris buffer instead of PBS. The activity of many enzymes and proteins is related to the concentration of metal ions. Desheng is an established manufacturer of biochemical buffers, which can supply more than ten kinds of biological buffers.
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