How do I choose the right biological buffer?

There are many factors to consider when choosing the right biological buffer. They are listed in the bulleted points below.

• The buffering range - Each buffer has its unique pH range in which the buffering capacity is at its maximum. This capacity is quantified by knowing the pKa of the buffer. One must choose a buffer that has a pKa value close to the middle of the necessary range, preferably within one pH unit of the desired pH.
• pH changes during the experiment - It is important to determine whether the pH will increase or decrease during the experiment. If the pH is expected to increase, one must choose a buffer with a pKa slightly higher than the ideal at the beginning of the experiment. If the pH is expected to decrease, one must choose a buffer with a lower pKa.
• The buffer concentration - The concentration of the buffer must be set correctly to have the most effective buffer capacity. If the concentration of a buffer is too low, it will not stabilize a solution’s pH. If the concentration is too high, the buffer is likely to influence the experiment. It is best to use concentrations higher than 25 mM. A concentration of 25-100 mM is preferred for buffer systems that don’t exchange hydrogen protons. When proton exchange is expected to occur, one must preferably use a buffer concentration that is 20x higher than the molarity of the protons being exchanged. It’s important to note to make the solution a concentration that’s intended to be used. 
• The temperature changes - The pH of a buffer solution must be set according to the temperature at which the experiment will be performed. Temperature directly affects the pKa of a buffer, as well as the pH and buffer capacity. In particular, setting the temperature is important which accurate hydrogen concentration is required to function at peak efficiency.

The pKa of some buffers, such as PIPES are not sensitive to temperature change, however other buffers like TRIS, ACES, TAPS, TES are more affected by these changes.