Question

How are viruses purified through precipitation?

Answer 1

Purification of viruses

1. Viruses are purified like proteins by precipitation with concentrated ammonium sulfate.
2. Initially, an adequate amount of ammonium sulfate is added to increase their concentration to a level just below which the virus gets precipitated.
3. This precipitates all the contaminants barring the virus.
4. The precipitated contaminants are eliminated.
5. Now, more ammonium sulfate is added to precipitate the viruses.
6. The precipitated viruses are accumulated further by centrifugation.
7. The viral pellet obtained is purified by precipitation with polyethylene glycol.