Hi all,

I have a sample of medium from which I want to precipitate ALL the proteins. Not one protein in particular. I need to know all the protein contaminants present in this sample. Will an ammonium sulphate precipitation do this? Or will it only precipitate some of the proteins? I'm currently using the TCA/acetone method, but I think it's too harsh on the proteins, and resuspending the pellet is a nightmare - I end up with dark brown chunks that I can't get into solution.

Any advice will be much appreciated!