Protein A/G Chromatography: Protein A and Protein G are affinity chromatography resins widely used for antibody purification. They selectively bind to the Fc region of immunoglobulins, allowing for efficient purification from crude samples. This technique is suitable for purifying monoclonal antibodies from cell culture supernatants or ascites fluid.
Ion Exchange Chromatography: Ion exchange chromatography separates proteins based on their net surface charge. It is particularly useful for purifying antibodies with different isoelectric points (pI). Anion exchange chromatography is employed for purifying antibodies with a net positive charge, while cation exchange chromatography is used for those with a net negative charge.
Size Exclusion Chromatography (SEC): SEC separates molecules based on their size and shape. It is a gentle technique that can be used for both initial purification and polishing steps. SEC is often employed to remove aggregates and other impurities from antibody samples obtained from previous purification steps.
Hydrophobic Interaction Chromatography (HIC): HIC separates proteins based on their hydrophobicity. Mild hydrophobic resins are used to capture antibodies under conditions of high salt concentration. This technique is effective for purifying antibodies that exhibit different hydrophobic properties from contaminants.
Affinity Chromatography: Apart from Protein A/G, various other ligands can be used in affinity chromatography for Antibody Purification Service. Examples include Protein L, which binds to the kappa light chain of antibodies, and antigen-based affinity chromatography, where specific antigens are used as ligands to capture antibodies with corresponding specificities.
Precipitation Techniques: Precipitation methods such as ammonium sulfate precipitation or polyethylene glycol (PEG) precipitation can be used for initial antibody purification. These techniques involve adding a precipitating agent to the sample, leading to the selective precipitation of antibodies, which can then be collected by centrifugation.
Magnetic Bead-Based Purification: Magnetic bead-based purification offers a rapid and scalable method for antibody purification. Antibodies can be conjugated to magnetic beads via various chemistries, allowing for easy separation using a magnetic field. This technique is particularly useful for high-throughput applications.
Ultrafiltration/Diafiltration: Ultrafiltration and diafiltration are membrane-based techniques used for concentrating and buffer exchanging antibody samples. They are often employed as a final polishing step to ensure the purity and stability of the purified antibody product.