precipitation with ammonium sulfate - (Nov/23/2004 )

I try to extract proteins from soil. I know I can use ammonium sulfate to precipitate proteins. But if I use ammonium sulfate on a solution containing proteins, humic acids, polysaccharides, and many components... what will I precipitate? Is it possible that ammonium sulfate precipitate humic acids ?

Can you help me?

Sandrine
France

In my opinion, ammonium sulfate precipitation technique will precipitate humic acids as well. This is similar to the salting out procedure.

As to how you are going to separate them, I am not sure. How about using the chromatography method?

Another point to consider is that: humic acids are insoluble in acidic condition (pH < 2) and soluble in the basic condition. Maybe you can look at this properties as well and try the multiple precipitation technique.

regards,
win804