Dear colleagues, I want to do reaction in pH 8.5, but not yet get the appropriate buffer. Bicarbonate carbonate buffer will give pH 9 and KH2PO4 NaOH buffer will end up the reaction at pH 7.5. Cannot using boric acid buffer, coz the by product, Na borate will be cytotoxic to the cell. Can anyone suggest the appropriate buffer at pH 8.5? Thank you in advance.
Mazita
There are several organic buffers available for pH 8.5. The cheapest and most widely available is Tris.
http://www.sigmaaldrich.com/life-science/core-bioreagents/biological-buffers/learning-center/buffer-reference-center.html
It depends on what reaction(s) you want to study. If you want to study enzymatic reactions, especially those catalyzed by catalyzed by hydrolases you must not use Tris buffer. Tris can be phosphorylated (Snyder, (Wilson, Biochemistry,11, 3220-3223 (1972) )or be acylated when it deacylates acyl-enzymes (especially peptidases) (Kasche, Zöllner, Hoppe Seyler´s Z. Physiol. Chem, 363, 531-534 (1982)). The uncharged amino group of Tris can act as a nucleophile in chemical reactions. This applies especially at pH>pKa of Tris. You must use an inert buffer that cannot participate in the reaction you want to study. Carbonate buffers are possible but they have a low buffer capacity at pH 8.5. You will find an extensive list of possible buffer and their properties in
https://www.applichem.com/fileadmin/Broschueren/BioBuffer.pdf
If you are trying to avoid Tris because of the primary amine, I would suggest Bicine. I used it in the past when carrying out a reaction with protein lysine residues.
- Badges
- Science topic
- Similar topics
- Computer Science and Engineering
- Bioinformatics
- Bioinformatic Tools