The sera are then purified by ammonium sulfate precipitation or affinity purification using a peptide column.
Addition of a neutral salt, such as ammonium sulfate, compresses the solvation layer and increases protein-protein interactions.
The main disadvantage to the use of ammonium sulfate is its low nitrogen content relative to ammonium nitrate, which elevates transportation costs.
This is performed by adding increasing amounts of ammonium sulfate and collecting the different fractions of precipitate protein.
It is an aqueous solution of ferrous ammonium sulfate, sorbitol, sulfuric acid and xylenol orange.
In the preliminary test, the ammonium sulfate concentration is increased stepwise, and the precipitated protein is recovered at each stage.
Ammonium sulfate is commonly used as its solubility is so high that salt solutions with high ionic strength are allowed.
The amount of ferrous ammonium sulfate added is equivalent to the amount of excess potassium dichromate added to the original sample.
