Don’t worry, this article isn’t about rats! Well, it kind of is. But it’s really about clones — clones of clones to be exact.

A group of biologists in Japan at the Riken Center for Developmental Biology have developed a breakthrough technique that has allowed them to create an endless line of clones. The method was built off of the original cloning technique that used to create the first ever cloned mammal in 1996, Dolly the sheep.

That original technique wouldn’t allow for cloning of clones due to an extremely low success rate, but this new method prevents genetic abnormalities by  prohibiting enzymes that alter DNA and cause the cloning to fail. While previous clones would die much sooner than their original counterparts, the clones that resulted from this experiment have reportedly live the normal lifespan of other mice.

So far, the scientists have managed to create 581 clone mice from the original donor mouse, which if you’re keeping count is 25 generations of clones. The researchers also believe that will be able to clone animals indefinitely: “Our results show that repeated iterative recloning is possible and suggest that, with adequately efficient techniques, it may be possible to reclone animals indefinitely.”

Sayaka Wakayama, who led the cloning study, believes that cloning animals could aid in different ways such as farming, or conservation of endangered species.

[via LiveScience, The Verge]