PIPES sodium salt

PIPES sodium salt buffer has been used:

• to prepare BRB80 buffer for imaging dynamic microtubules and single kinesin molecules through fluorescence microscopy
• as a component of PEM fixation solution
• to reconstitute red blood cells (RBCs) to study the effect of pH on 5-coordinate alpha-nitrosyl-hemoglobin (HbNO) stability

1, 4-piperazinediethanesulfonic acid (PIPES) is a zwitterionic buffer that belongs to the group of the ethanesulfonic acid buffer series, first introduced by Good et al., It is a non-toxic buffer used in cell culture and tissue fixation for electron microscopy and other biological applications. PIPES don’t interact with metal ions. Since its pK_a at 37°C is near physiological pH, it has been used as a buffering substance in biological, biochemical, and environmental studies. PIPES is developed to meet certain criteria: midrange pK_a, maximum water solubility and minimum solubility in all other solvents, minimal salt effects, minimal change in pK_a with temperature, chemically and enzymatically stable, minimal absorption in visible or UV spectral range and easily synthesized. Buffers can be prepared by adding a solution of the 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.