Chromatography Forum

I am an RA purifying cytokines and we exclusively use Q and S resins for capture/intermediate purification. We have DEAE and CM resins also, but I have never used them.

I understand that Q and S are strong exchangers that will hold their charge over a broad pH range; versus DEAE and CM which are used in a more narrow pH range. But I don't understand what situation I would use the weak exchangers in.


Thanks

Joey

You sort of answered your own question: when you need to control the ion exchange capacity of the stationary phase by changing the pH. As an example, you can have an analyte bind to the stationary phase and then release it completely via a pH change.

Speaking personally, I prefer to work with the strong exchangers, because there is one less parameter to worry about. I know people who prefer the weak exchangers because there is one more parameter that they can use to tweak the chromatography.