According to the TEACH Act, if a digital copy of an item is available to the institution, that copy must be purchased and used. If such a copy is not available, you may digitize only as much of an item as is allowed under fair use guidelines. Academic best practice recommends that you digitize no more than 10% of the content or three minutes, whichever is less. Digitizing the entire DVD or VHS tape is not allowed without the permission of the copyright holder.