HEPES Buffer 0.5M, pH 9.0

HEPES, also referred to as 4-(2-Hydroxyethyl)piperazine-1-ethanesulfonic acid, is an N-substituted aminosulfonic acid buffer with an optimal buffering pH range of 6.0 to 8.5. HEPES, when applied as a separator in ultrathin isoelectric focusing gels, enhances phosphoglucomutase resolution. HEPES is zwitterionic at most biological pHs making it one of the best all-purpose buffers available for use in biological research. It is also catogorized under Good's buffers. HEPES may be used in isoelectric focusing applications and as a buffer in the quantitative and selective measurement of antigen-antibody reactions. HEPES is reportedly superior to NaHCO in controlling pH in tissue and organ culture. Not recommended for use with the Folin-Ciocalteu protein assay.