I didn't find any instance of memory reuse in the Harry Potter books. Once it's in the Pensieve and watched, it's never indicated if it can be taken out again and reviewed.

One counterexample one can use is the first memory of Slughorn, but it could be said from just looking at it that it was tampered with, it was not required to watch it.

Was it possible to reuse memory strands from the Pensieve after watching them? Note that I'm not talking about just storing, but reusing.