Protocol Online logo
Top : Forum Archives: : Protein and Proteomics

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 cottin-

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.