What are the Common Methods of Protein Precipitation?

Several methods are employed for protein precipitation, each with its advantages and limitations:

1. Organic Solvent Precipitation: Commonly used solvents include acetone and acetonitrile. These solvents reduce the solubility of proteins, causing them to precipitate.
2. Salt-Induced Precipitation: Salts such as ammonium sulfate can be used to precipitate proteins by altering their solubility.
3. pH-Induced Precipitation: Adjusting the pH to the isoelectric point (pI) of the protein can lead to precipitation.
4. Temperature-Induced Precipitation: Heating or cooling can induce protein precipitation by affecting their solubility and stability.
5. Polyethylene Glycol (PEG) Precipitation: PEG can be added to the solution to facilitate protein aggregation and precipitation.