There are so many types of biological buffers, I believe I don’t need to say more, people know it whether they understand or don’t. Therefore, there are many uncertainties in our choice. I don't know which is what you need and which is suitable. In response to this problem, Desheng, as a manufacturer of biological buffers, teaches you how to choose.
1. Buffer range
Each buffer has the highest buffering capacity in the pH range. This capacity is usually determined by the pKa of the buffer. You must choose a buffer with a pKa value close to the middle value of the desired range (usually, it is recommended to use a buffer with a pKa value at least within one pH unit of the target pH value).
2. pH changes during the experiment
It is important to consider whether the pH may increase or decrease during the experiment. If you expect the pH to increase, you must choose a buffer with a pKa slightly higher than the optimal value at the beginning of the experiment. The opposite is also true: if you expect a decrease in pH, choose a buffer with a lower pKa.
3. Buffer concentration
The concentration of the buffer must be adjusted to have sufficient capacity for the experimental system. In short, if the concentration of the buffer is too low, it will not be able to stabilize the pH of the solution. Conversely, if the concentration is too high, the buffer is likely to affect the experiment. Generally, it is recommended to use a concentration higher than 25 mM.
For systems that do not actively exchange hydrogen protons, the recommended concentration is usually 25-100 mM. For systems where proton exchange may occur, it is recommended to use a buffer concentration 20 times higher than the molar concentration of exchanged protons.
When preparing the buffer solution, remember to adjust the concentration of the solution to the intended use concentration.
4. Temperature changes
The pH of the buffer solution must be set according to the temperature at which the experiment will be performed. Temperature directly affects the pKa of the buffer, which in turn affects the pH value and buffering capacity of the system. This situation may be very critical in biological systems. In biological systems, accurate hydrogen ion concentration is required to make the reaction system run at maximum efficiency.
The pKa of some buffers (such as PIPES) is less sensitive to temperature changes, but other options (such as TRIS, TAPS, TES, or Tricine) are more affected by these changes.
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