What is the difference between piperazine diethanesulfonic acid PIPES and phosphate buffer

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Piperazine diethanesulfonic acid PIPES is a biological buffer commonly used in biological experiments, usually used in protein or cell-related research experiments. Compared with phosphate buffer, it has many advantages. In many demanding experiments, PIPES needs to be used instead of PBS buffer.


There are many buffers commonly used in biology. In addition to PIPES buffer and PBS, there are Bicine, Tris, MOPS, etc. In many reaction systems involving enzymes, if the enzyme or protein needs to have metal ions to show activity, then a buffer that does not form complexes with metal ions is needed. The characteristic of PIPES is that it will not form stable complexes with most metal ions, and is suitable for solution systems containing metal ions.


Piperazine diethanesulfonic acid PIPES powder reagent


Among the many biological buffers in biochemical experiments, the most widely used is phosphate buffer. Phosphoric acid is a tribasic acid. Since phosphoric acid is a secondary dissociation and has two pKa values, the buffer solution prepared with phosphate has a very wide pH range. Generally speaking, the potassium salt of phosphate is better than sodium salt, because sodium salt is insoluble at low temperature, while potassium salt is easily soluble. However, when preparing the buffer for SDS-polyacrylamide gel electrophoresis, only sodium phosphate can be used, because SDS will generate insoluble potassium lauryl sulfate with potassium salt.


Phosphate buffer solution has a wide applicable pH range and low temperature influence. The pH change after ten times dilution is less than 0.1. In a solution system with metal ions, the phosphoric acid system will associate with common Ca, Mg ions and heavy metal ions to form a precipitate.


For example, carboxypeptidase B (exocrine protease) contains one Zn atom per molecule. Because it is an enzyme containing metal atoms, metal ion chelating agents such as EDTA can inhibit enzyme activity. Therefore, carboxypeptidase B is used for protein and peptide sequencing. When reacting the system, the system must not contain EDTA and a buffer that can complex zinc ions.


Piperazine diethanesulfonic acid PIPES contains ethanesulfonic acid group, but its hydrophilicity is not as good as that of HEPES containing hydroxyl. Sodium hydroxide lye is needed to dissolve it. Desheng’s PIPES is the raw material for the preparation of buffer solutions and is a powder reagent. If you need its buffer solution, you can also consult the technical staff for the solution preparation method.