View source for PIPES

{{about|the biochemical [[buffer solution|buffer]] PIPES|other uses|Pipe (disambiguation)}}
{{chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 450879654
| Name = PIPES
| ImageFile = PIPES.svg
| ImageName = Chemical structure of PIPES
| PIN = 2,2{{prime}}-(Piperazine-1,4-diyl)di(ethane-1-sulfonic acid)
| OtherNames = PIPES
|Section1={{Chembox Identifiers
| CASNo_Ref = {{cascite|correct|??}}
| CASNo = 5625-37-6
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = G502H79V6L
| PubChem = 6992709
| ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}}
| ChemSpiderID = 72022
| SMILES = C1CN(CCN1CCS(=O)(=O)O)CCS(=O)(=O)O
| InChI = 1/C8H18N2O6S2/c11-17(12,13)7-5-9-1-2-10(4-3-9)6-8-18(14,15)16/h1-8H2,(H,11,12,13)(H,14,15,16)
| InChIKey = IHPYMWDTONKSCO-UHFFFAOYAG
| StdInChI_Ref = {{stdinchicite|changed|chemspider}}
| StdInChI = 1S/C8H18N2O6S2/c11-17(12,13)7-5-9-1-2-10(4-3-9)6-8-18(14,15)16/h1-8H2,(H,11,12,13)(H,14,15,16)
| StdInChIKey_Ref = {{stdinchicite|changed|chemspider}}
| StdInChIKey = IHPYMWDTONKSCO-UHFFFAOYSA-N
 }}
|Section2={{Chembox Properties
| Formula = C<sub>8</sub>H<sub>18</sub>N<sub>2</sub>O<sub>6</sub>S<sub>2</sub>
| MolarMass = 302.37
| Appearance = White powder
| Solubility = 1 g/L (100 °C)
| MeltingPt = Decomposes above 300 °C
| BoilingPt = Decomposes
 }}<!--
| [[Acid dissociation constant|Acidity]] (p''K''<sub>a1</sub>), (p''K''<sub>a2</sub>
|<3, 6.8
|-
 -->
|Section7={{Chembox Hazards
| ExternalSDS = [http://hazard.com/msds/mf/baker/baker/files/p4789.htm External MSDS]
| MainHazards = Irritant
| NFPA-H = 1
| NFPA-R = 0
| NFPA-F = 0
 }}
}}

'''PIPES''' ('''piperazine-''N'',''N{{prime}}''-bis(2-ethanesulfonic acid)''') is a frequently used [[buffering agent]] in [[biochemistry]]. It is an [[ethanesulfonic acid]] buffer developed by Good et al. in the 1960s.<ref>{{cite journal|doi=10.1021/bi00866a011|title=Hydrogen Ion Buffers for Biological Research|year=1966|last1=Good|first1=Norman E.|last2=Winget|first2=G. Douglas|last3=Winter|first3=Wilhelmina|last4=Connolly|first4=Thomas N.|last5=Izawa|first5=Seikichi|last6=Singh|first6=Raizada M. M.|journal=Biochemistry|volume=5|pages=467–77|pmid=5942950|issue=2}}</ref>

==Applications==
PIPES has two [[Acid dissociation constant|pKa]] values. One [[pKa]] (6.76 at 25&nbsp;°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&nbsp;°C. The second [[Acid dissociation constant|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 [[fixation (histology)|histology]] in plant and animal [[tissue (biology)|tissue]]s.<ref>Salema, R. and Brando, I., J. Submicr. Cytol., 9, 79 (1973).</ref><ref>Schiff, R.I. and Gennaro, J.F., Scaning Electron Microsc., 3, 449 (1979).</ref> Fungal [[zoospore]] fixation for [[fluorescence microscopy]] and [[electron microscopy]] were optimized with a combination of [[glutaraldehyde]] and [[formaldehyde]] in PIPES buffer.<ref>{{cite journal|author=Hardham, A.R.|journal=Journal of Histochemistry|volume= 33|pages=110–8|year=1985|title=Studies on the cell surface of zoospores and cysts of the fungus Phytophthora cinnamomi: The influence of fixation on patterns of lectin binding|url=http://www.jhc.org/cgi/content/abstract/33/2/110|pmid=3918095|issue=2|doi=10.1177/33.2.3918095|doi-access=free}}</ref> It has a negligible capacity to bind [[divalent]] ions.<ref>{{cite web|title=Hopax Fine Chemicals - Biological buffers and their interactions with metal ions|url=https://www.hopaxfc.com/en/blog/biological-buffers-and-their-interactions-with-metal-ions}}</ref>

==See also==
*[[MOPS]]
*[[HEPES]]
*[[MES (buffer)|MES]]
*[[Tris]]
*[[Buffer solution#Common buffer compounds used in biology|Common buffer compounds used in biology]]
*[[Good's buffers]]

==References==
{{reflist|2}}

{{Piperazines}}

[[Category:Buffer solutions]]
[[Category:Sulfonic acids]]
[[Category:Piperazines]]


{{biochem-stub}}