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Chemical structure of PIPES
IUPAC name
1,4-Piperazinediethanesulfonic acid (IUPAC)
Other names
3D model (JSmol)
ECHA InfoCard 100.024.598
Molar mass 302.37
Appearance White powder
Melting point Decomposes above 300 °C
Boiling point Decomposes
1 g/L (100 °C)
Main hazards Irritant
Safety data sheet External MSDS
NFPA 704 (fire diamond)
Flammability code 0: Will not burn. E.g. waterHealth code 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineReactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no codeNFPA 704 four-colored diamond
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

PIPES is the common name for piperazine-N,N′-bis(2-ethanesulfonic acid), and is a frequently used buffering agent in biochemistry. It is an ethanesulfonic acid buffer developed by Good et al. in the 1960s.[1]


PIPES has two pKa values. One pKa (6.76 at 25°C) is near the physiological pH which makes it useful in cell culture work. Its effective buffering range is 6.1-7.5 at 25° C. The second pKa value is at 2.67 with a buffer range of from 1.5 - 3.5. PIPES has been documented minimizing lipid loss when buffering glutaraldehyde histology in plant and animal tissues.[2][3] Fungal zoospore fixation for fluorescence microscopy and electron microscopy were optimized with a combination of glutaraldehyde and formaldehyde in PIPES buffer.[4] It has a negligible capacity to bind divalent ions.

See also[edit]


  1. ^ Good, Norman E.; Winget, G. Douglas; Winter, Wilhelmina; Connolly, Thomas N.; Izawa, Seikichi; Singh, Raizada M. M. (1966). "Hydrogen Ion Buffers for Biological Research". Biochemistry. 5 (2): 467–77. doi:10.1021/bi00866a011. PMID 5942950.
  2. ^ Salema, R. and Brando, I., J. Submicr. Cytol., 9, 79 (1973).
  3. ^ Schiff, R.I. and Gennaro, J.F., Scaning Electron Microsc., 3, 449 (1979).
  4. ^ Hardham, A.R. (1985). "Studies on the cell surface of zoospores and cysts of the fungus Phytophthora cinnamomi: The influence of fixation on patterns of lectin binding". Journal of Histochemistry. 33 (2): 110–8. doi:10.1177/33.2.3918095. PMID 3918095.