A phosphate buffer is a buffer solution that is widely used in biological experiments, and is highly water soluble, with a high buffering capacity. It can be used in several pH levels, due to phosphoric acid having 3 dissociation constants, with pH levels of approximately 2.5, 6.86 or 12.32. Phosphate buffers inhibit enzymatic processes and precipitates in ethanol but are still one of the most common buffers currently in use.