Hello,
I would like to prepare a 20 mM reduced glutathione solution with pH=7. It's common to use PBS 1X to have this pH value. And in every publication, they "prepared GSH in PBS with pH=7,4". However, when I prepared it, I'm with a pH of 3,8... There is a problem with my initial PBS solution or I need to adjust the pH by myself? Because, for me, the PBS buffer was supposed to make the job?
Thanks :)
The only way to be sure about the pH is to check and adjust it (if needed) after complete GSH solubilisation.
Note that the higher the pH, the lower the stability of GSH in solution. For example, the half-life of GSH drops from 16 h to 9 h when the pH is adjusted from 6.5 to 7.5 (Stevens et al. 1983).
Article The stabilities of various thiol compounds used in protein p...
Glutathione is an acid, which is why the pH is coming out lower than that of the buffer. The buffer is not strong enough to prevent the pH change. Titrate the pH back to neutral with 1 equivalent of base, or use a more concentrated buffer.
- Badges
- Science method