HEPES, sodium salt

HEPES, sodium salt: This product is designated as Biotechnology Performance Certified (BPC) reagent grade and meets the specifications of the USP, EP, and JP for reagent chemicals. In addition, this product can be used for molecular biology, cell culture, and electrophoresis applications. HEPES does not bind magnesium, calcium, manganese (II), or copper (II) ions. HEPES has been described as one of the best all-purpose buffers available for biological research. At most biological pHs, the molecule is zwitterionic, and is most effective as a buffer at pH 6.8 to 8.2 (pK±1, as a general rule). HEPES has been used in a wide variety of applications, including tissue culture. Buffer strength for cell culture applications is usually in the range of 10 to 25 mM. Care must be taken to maintain appropriate osmolality in media, and toxicity with respect to a given cell line must be evaluated. Isotonicity data have been tabulated. HEPES is reportedly superior to NaHCO3 in controlling pH in tissue and organ culture. Unfortunately, HEPES is not recommended for certain protein applications. It interferes with the Folin- Ciocalteu protein assay. The Biuret protein assay is unaffected. HEPES was the buffer of choice in a protein deposition technique in electron microscopy because it did not affect metal substrates. HEPES was evaluated and shown to be quite suitable for use with Ampholines in generating pH gradients less than 1 pH unit wide for isoelectric focusing applications.