Chester Zoo freezing tissue samples of rare animals to save them from extinction

Conservationists at Chester Zoo have begun freezing tissue samples of the world’s rarest animals in the battle to save hundreds of species such as rhinos and jaguars from extinction.The zoo’s scientists have teamed up with some of the UK’s leading animal reproduction experts to form Nature’s SAFE – one of Europe’s largest biobanks dedicated to preserving and regenerating the cells of the planet’s most precious animals.

Small tissue samples from ovaries, testicles and ears are taken from animals that have passed away at the zoo and, using state-of-the-art technologies, are cryogenically frozen at temperatures of -196°C using liquid nitrogen.Scientists say that in the future, as reproductive technologies advance, the frozen tissue samples may be used to further conserve species globally by generating sperm and eggs - which will enable conservationists to restore animal species threatened with extinction.Thanks to contributions from Chester Zoo, the frozen living biobank has successfully preserved cell types from more than 100 highly threatened animal species, including the critically endangered Eastern black rhino, mountain chicken frog, Javan green magpie and jaguar.

Dr Sue Walker, Head of Science at Chester Zoo and Co-Founder of Nature’s SAFE, said: “With gene pools and animal populations continually shrinking in the wild, the work of modern conservation zoos like ours has never been more important.

"Technologies, such as cryopreservation, offers us a new, critical piece of the conservation puzzle and helps us provide a safeguard for many of the world’s animals that, right now, we’re sadly on track to lose.”