HEPES (4-(2-Hydroxyethyl)piperazine-1-ethane-sulfonic acid) has been described as one of the best all-purpose buffers available for use in biological research. The molecule is zwitterionic at most biological pHs and is most effective as a buffer at pH 6.0 to 8.5. 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 NaHCO3 in controlling pH in tissue and organ culture. Not recommended for use with the Folin-Ciocalteu protein assay.
Storage
Store at room temperature
Usage
• Recommended working concentration: 10-25 mM
• A buffer solution of HEPES can be prepared by any of several methods. The free acid can be added to water, then titrated with sodium hydroxide or potassium hydroxide to the pH desired. Alternatively, equimolar concentrations of HEPES and of sodium HEPES (sc-216092) can be mixed in approximately equal volumes, back-titrating with either solution to the appropriate pH.
• This product is a high quality reagent, but has not been evaluated for use in cell culture. Please employ appropriate contaminant testing and/or sterilization techniques for the intended application.
