Rapid purification of monoclonal antibodies using magnetic microspheres.

Magnetic microspheres represent an interesting alternative to conventional chromatography resins in automated high-throughput protocols replacing centrifugation and filtration by magnetic separation. Some magnetic microspheres have unique features like high magnetite content and non-porous surface which allows them to migrate very fast in magnetic fields while binding target molecules with a low unspecific adsorption. Here, we describe the use of protein A or protein G-coated magnetic microspheres to purify quickly monoclonal antibodies from crude serum-free supernatants without the need of preliminary clarification or purification step. Using this method, multiple samples can be processed in parallel, a high level of purity can be obtained, and the purified IgG maintain their biological activity.