N-Acetylcysteine - (Aug/11/2009 )

This compound drops the pH significantly. I prefer to make fresh everytime, but I'm worried that the pH is interfering with the results. For those that have successfully used this chemical in experiments, what is your preferred method for preparing working solutions? Do you make stock solutions and then titrate the stock with NaOH?

After much trial and error, I've found the best thing that works for me is to make it fresh. I make it at the concentration at which I plan to use it (10mM, for example) in the media I use for my cells (warming up the media first helps it to dissolve). I then use NaOH to bring it back up to pH 7.2. Once I'm happy with the pH, I run it through a 0.22 micron filter to sterilize the solution and resuspend my cells in it.

Making it at too high of a concentration (100mM+) makes it impossible to filter. Some people freeze aliquots of the solution, but since it's not all that stable in solution, I think fresh is probably best.

Thanks, appreciate the input!