Q:

In the Harry Potter universe, can memories stored in vials only be used once?

In the Harry Potter films, characters seem to pour the contents of memory vials out completely (at least as far as I can tell).  Does that mean that memories can only be used once? 

A:

In the books, the memories can be put back into a vial after use. That memories are reusable should be clear from the fact that Dumbledore shows Harry memories he himself has seen before individually.

