Common methods used for viral vector purification include ultracentrifugation, chromatography, filtration, and tangential flow filtration (TFF). Ultracentrifugation allows separation of viral vectors based on density gradients, while chromatography techniques such as ion exchange, size exclusion, or affinity chromatography can be employed to selectively capture and purify the viral vectors. Filtration methods remove larger particles and contaminants, while TFF enables concentration and diafiltration of the viral vector preparations.