Protein PurificationExtraction and Clarification
Before the first chromatography step it is necessary to remove unbroken cells, lipids, and particulate matter from the protein solution.
For some applications it is sufficient to use a low centrifugation step: 15 min at 10,000 g (e.g. 15,000 rpm using a Sorvall SS-34 rotor).
When a very clear sample is needed, e.g. for refolding or when the sample is directly applied to an expensive chromatography column, an ultracentrifugation step becomes necessary: 30 min at >100,000 g (45,000 rpm using a Beckman 45Ti rotor).