HEPES for buffer solutions

Comments

About HEPES - HEPES is a short name for 2-(4-(2-hydroxyethyl)-1-piperazinyl)-ethanesulfonic acid, a buffer substance. - Chemical properties - HEPES is used for biochemical, molecular biological and microbiological purposes as a buffer substance from the group of good buffers. With an acid constant of pKs = 7.55 (at 20 °C), it has a good buffering capacity between pH 6.8 and 8.2. The temperature dependence is ΔpKs/ΔT = -0.014 K-1.
HEPES is a widely used buffer in biological studies. There is only one restriction in the use of this buffer, because it interferes with the Folin protein assay. In cell culture media, it is employed as a substitute for the bicarbonate buffer at a concentration of 25 mM or as a supplement to the bicarbonate buffer (concentration 10 - 15 mM).The addition of 20 mM HEPES to TBE buffer improves the migration behaviour of certain samples in the SSCP analysis (single-strand conformation polymorphism), with a higher resolution especially if small differences in the sequences between certain bands are wanted (5).

Literature

(1) Good, N.E. et al. (1966) Biochemistry 5, 467-477. Synthesis and characterization of various 'H+ buffers' for biological research. (2) Shipman, C. (1969) Proc. Soc. Exp. Biol. Med. 130, 305-310. HEPES as a buffer in cell culture. (3) Good, N.E. & Izawa, S. (1972) Methods Enzymol. 24, 53-68. Further discussion on the selection of buffers in biological research, here with emphasis on their suitability for the study of photosynthetic processes. (4) Ferguson, W.J. et al. (1980) Anal. Biochem. 104, 300-310. Buffers to buffer hydrogen ions for biological research: synthesis of other buffers and test in cell culture, plant pathology, and virology. (5) Grady, J.K. et al. (1988) Anal. Biochem. 173, 111-115. Radicals from Good buffers. (6) Liu, Q. & Sommer, S.S. (1998) Biotechniques 25, 50-56. The SSCP phenomenon: addition of HEPES affects electrophoretic mobility.