How would you readily purify monoclonal antibody in a singl

How would you readily purify monoclonal antibody ( in a single step) from serum-free cell culture supernatant of a hybridoma , even though you do not know the indentity of the antigen? What problem would you encounter if you used the above method with hybridoma cell culture media that contained bovine serum, which is normally used to grow hyhbridoma cells in culture?

Solution

Monoclonal antibodies, being immunoglobulins, can be purified in a single step from serum-free cell culture supernatant of a hybridoma by using ammonium sulfate precipitation method; ammonium sulfate (c. 19.5% in 2.03% sodium chloride) readily precipitates immunoglobulins.

If, however, the hybridoma cell culture media contains bovine serum, other proteins present in the bovine serum that are heavier than immunoglobulins will also be precipitated by ammonium sulfate along with the monoclonal antibody.