HEPES

Description

In biological experiments, it is important to maintain the pH of the solutions used. Buffers, mixtures of appropriate weak acids, and their conjugate bases, are usually used. Most biological reactions occur at a neutral pH, from 6 to 8; the buffer needs to be effective in this range. Furthermore, the acids and bases used in the buffer should not produce chelates with metal ions, which are essential in biological systems. For these reasons, Dr. Good developed several aminoethane and aminopropane sulfonic acids that are now widely used for biological research and analysis. Good's buffers have the following characteristics:

1. High water-solubility
2. Low cell membrane permeability
3. Consistent acid-base dissociation constants
4. Low metal chelating capability
5. High chemical stability
6. Low absorption spectra in UV and visible regions.