description
PIPES free acid, also known as 1,4-piperazinediethanesulfonic acid, is a Good's buffer notable for having a pKa value similar to ordinary physiological pH. As such, PIPES free acid is frequently used as a buffer in biochemical research.
PIPES is a zwitterionic, piperazinic buffer that is useful for a pH range of 6.1 – 7.5. PIPES lacks the ability to form a significant complex with most metal ions and is recommended for use as a non-coordinating buffer in solutions with metal ions. PIPES has wide variety of applications and is commonly used in cell culture media, in protein crystallization, as a running buffer in gel electrophoresis, and as an eluent in isoelectric focusing and chromatography. This buffer is capable of forming radicals and is therefore not suitable for redox reactions. It is suitable for use in the bicinchoninic acid (BCA) assay. Solubility of PIPES increases when the free acid is converted to the sodium salt.
Buffers are made by adding base solution to PIPES free acid and titrating to the desired pH.
Uses
Piperazine-N, N'-bis- (2-ethanesulphonic acid) ultra -pure >99.5%) is an important chemical intermedia in all kinds of chemical fields. 1,4-Piperazinediethanesulfonic acid, piperazine-N, N’-bis- (2-ethanesulfonic acid) (PIPES) is also one of the zwitterion buffers and the most appropriate buffer for the biological experiments using an intracellular solution since the Pk2 of Pipes is 6.8 at 20 degrees Celsius.
Description
PIPES is a member of the ethanesulfonic acid buffer series, first introduced by Good et al., developed to meet certain criteria: midrange pKa, maximum water solubility and minimum solubility in all other solvents, minimal salt effects, minimal change in pKa with temperature, chemically and enzymatically stable, minimal absorption in visible or UV spectral range and easily synthesized. Since its pKa at 37 °C is near physiological pH, PIPES has applications in cell culture work.
Chemical Properties
White/clear crystalline powder
Uses
A buffering agent with a pKa near physiological pH.PIPES [piperazine-N,N′-bis(2-ethanesulfonic acid)] is frequently used as a buffering agent in biochemistry. It is an ethanesulfonic acid buffer developed by Good et al. in the 1960s. PIPES has a pKa near the physiological pH which makes it useful in cell culture work. It has been documented to minimize lipid loss when buffering glutaraldehyde histology in plant and animal tissues.
Additional forms available: PIPES, Sesquisodium Salt ; PIPES dipotassium salt; PIPES disodium salt; PIPES, Sodium Salt. Buffers can be prepared by adding a solution of base to PIPES free acid, titrating to the appropriate pH, or by mixing equimolar solutions of the monosodium salt and the disodium salt, titrating to the appropriate pH.
Uses
Protocols have been reported on the use of PIPES for separation of glyoxylated RNA in agarose gels, nuclease S1 mapping of RNA, and in ribonuclease protection assay protocols. PIPES has been used as a buffer in glutaraldehyde fixation of tissue samples.
, PIPES has been utilized in protein crystallization.
, The use of PIPES in the reconstitution of dissociated tubulin
α and β subunits after their resolution on immunoadsorbent gels has been described. PIPES has been recommended for use in buffers for the
in vitro study of caspases 3, 6, 7, and 8.
A published study demonstrated the usefulness of PIPES as a non-metal ion complexing buffer in such applications as protein assays. PIPES has been used in cell culture for such applications as the engineering of a thermostable mutant membrane protein in
Escherichia coli.
Definition
ChEBI: 2,2'-piperazine-1,4-diylbisethanesulfonic acid is a Good's buffer substance, pKa = 6.8 at 20 ℃. It is a conjugate acid of a 2,2'-piperazine-1,4-diylbisethanesulfonate.
Application
Glutaraldehyde fixation of plant and animal tissue samples can cause loss of lipid, leading to apparent morphological changes. Lipid loss and artifacts were minimized when PIPES was used to buffer the glutaraldehyde fixative.
Alkaline phosphatase activity is lost selectively from certain rat hepatocyte organelles when fixed for ultracytochemistry with cacodylate-buffered glutaraldehyde. When PIPES was used as buffer, retention of activity was 60% greater.
Fixation of fungal zoospores for fluorescence microscopy and electron microscopy was optimal with a combination of glutaraldehyde and formaldehyde in PIPES buffer.
General Description
PIPES is a member of the ethanesulfonic acid buffer series, first introduced by Good et al., developed to meet certain criteria: midrange pKa, maximum water solubility and minimum solubility in all other solvents, minimal salt effects, minimal change in pKa with temperature, chemically and enzymatically stable, minimal absorption in visible or UV spectral range and easily synthesized. Since its pKa at 37 °C is near physiological pH, PIPES has applications in cell culture work.
Flammability and Explosibility
Not classified
Purification Methods
Purify PIPES from boiling water (maximum solubility is about 1g/L) or as described for ADA [N-(2-acetamido)iminodiacetic acid above]. [Good et al. Biochemistry 5 469 1966, Beilstein 23/12 V 380.]
