Sperm in frozen animals still viable years later

Sperm stored inside frozen organs or whole animals can produce healthy offspring years later, a new study shows.

Researchers bank sperm from lab animals and other species that they may want to reproduce in the future. The typical method for storing male sex cells involves dissecting the epididymides—tubes that store sperm in the testes—from dead animals. Researchers remove the sperm, which are then placed in a special preservative solution and plunged into liquid nitrogen.