- Wash and re-precipitate: After PEG precipitation, wash the pellet and re-precipitate it using 20% sucrose cushion ultracentrifugation. This removes a large portion of PEG co-precipitated molecules.
- Resuspend in serum-free media: Resuspend the pellet in serum-free media or PBS, then spin in a microfuge to pellet the protein debris followed by 20% sucrose cushion ultracentrifugation.
- Use activated carbon: Add activated carbon to the solution, then remove it by centrifugation or filtration.
