Abstract: The present invention relates to the purification of large scale quantities of active (infectious) adenovirus and AAV, especially for use in therapeutic applications. In particular, the invention provides improved methods for contacting such viruses with suitable chromatographic materials in a fashion such that any damage to the virus, particularly to surface components thereof, resulting from contact with such chromatographic materials is minimized or eliminated. The result is the ability to rapidly and efficiently purify commercial level quantities of active (infectious) virus suitable for use in therapeutic applications, e.g. gene transfer/therapy procedures.