Instructions for use of piperazine-1,4-diethylsulfonic acid PIPES

Piperazine-1,4-diethylsulfonic acid PIPES, CAS No. 5625-37-6, is a widely used biochemical reagent, with a white powder appearance and weak acidity, usually dissolved in NAOH aqueous solution to make a biological buffer The buffer range is 6.1-7.5, suitable for neutral weak acid buffer system.

PIPES buffer configuration:

PIPES is different from other buffers. It is not directly dissolved in water, but is first prepared with an aqueous solution of sodium hydroxide, then weighed according to the molecular weight of PIPES 302.368, directly dissolved in aqueous NaOH solution, and then used a lower concentration of NaOH solution Adjust the pH of the buffer. The following is the reference configuration method of 0.1M PIPES buffer solution, the temperature is maintained at 20 ℃.

A. With 0.1M solution (A)

(Ⅰ)NaOH/deionized water=4g/400ml …①

(Ⅱ) "①+PIPES 30.237g"...②

(Ⅲ)②+Deionized water (about 600ml)=1,000ml

B. With 0.1M NaOH solution (B): NaOH 4g/deionized water 1,000ml

C. pH 5.6 1,000ml(A)+0ml(B) (A):(B)=5:0

    pH 6.4 1,000ml(A)+200ml(B) (A):(B)=5:1

    pH 6.8 1,000ml(A)+400ml(B) (A):(B)=5:2

    pH 7.2 1,000ml(A)+600ml(B) (A):(B)=5:3

    pH 7.7 1,000ml(A)+800ml(B) (A):(B)=5:4

The differences between PIPES buffer and phosphate buffer:

Generally, more buffers used in biochemical experiments are phosphate buffers, and phosphoric acid is a tribasic acid. Because they are second-order dissociated and have two pKa values, phosphates can be easily configured into buffers of various concentrations. The pH range is wide, the pH is less affected by temperature, the pH change after dilution is small, and the pH change after dilution is less than 0.1. However, in a solution system with metal ions, the phosphoric acid system will associate with common Ca ions, Mg ions, and heavy metal ions to form a precipitate.

PIPES is different. Unlike Bicine and Bis-Tris which have coordination groups, they cannot form complexes with most metal ions such as calcium and magnesium ions. In biochemical reactions, many proteins and enzymes are affected by metal ions. When using phosphate buffers, PIPES is more suitable as a buffer in metal ion-containing solution systems. However, PIPES can form free radicals and is not suitable for buffers in redox systems.

When choosing a biological buffer, not only the buffer range to be considered, but also the suitability and limitations of the experimental system, although phosphate buffering performance is good, but certain conditions require the use of PIPES. Desheng company is a manufacturer specializing in the production of various types of biological buffers, you can directly consult any related needs!