As the previous posters have said, proper quarantine means keeping any new additions isolated from your collection to avoid spreading disease and/or parasites. Ideally this would be in a different room or different area of your house, but if that's not possible, as far away from the rack as you can in the room. There are some other steps you should take, such as not using the same feeding tongs, always wash hands between handling, always handle your existing collection before handling the QT snakes, etc...