Why and how we use animals


Research using animals has played a part in many of the medical advances we now take for granted. These include vaccines and antibiotics to prevent and treat infections, drugs used in surgery, and treatments for diseases such as cancer, heart disease and stroke.

New Approach Methods or Non Animal Methods, both translating to the acronym NAM, have been and are being developed, such as cultivating human cells in the lab and the production of ‘mini organs’ to carry out experiments on. Some of them replace the use of animals entirely, others lead to reduced animal numbers. 

Our bodies and minds are complex and we haven’t succeeded in recreating all biological systems and their interactions in the lab yet. Our scientists still need to use animals to study conditions such as cancer, infectious diseases and developmental problems. 

We know that all research methods have their uses and their limitations. We continue to question the validity of our animal models and engage in discussions about the value of scientific results from animal studies.

Caetano Reis e Sousa and his team are studying ways that the immune system could be harnessed to target and destroy cancer cells.

Their work with mice in the the Biological Research Facility has the potential to deliver more effective treatments and new vaccines for cancer and infectious diseases in the future.
Find out more about the vital role that animal research plays in his work at the Crick in this video from Wellcome.


Animals at the Crick

Our scientists continue to get meaningful results from research involving animals. Different animals are used for different types of research. 

Mice & rats

We use mice to explore how genes work in various diseases. We have different genetically modified animals to help researchers pinpoint exactly the effects of these genetic changes. We occasionally use rats for their serum that is used immediately after blood collection.


We maintain the only UK colony of laboratory opossums, which we use to study sex chromosomes. Opossums are marsupials, and studying how the genetics of their sex chromosomes compare to that in humans teaches us about fertility and development.


We use African clawed frogs for developmental biology research. Scientists have learned a lot about development from frogs because they are relatively easy to work with: they lay lots of eggs and their embryos develop outside the body, for example.


We keep less than five ferrets at any time to study flu, because they are the only animals that catch the same flu viruses as humans. The World Health Organization Worldwide Influenza Centre here at the Crick use them to help develop flu vaccines and identify potentially pandemic strains of flu.

Guppies & zebrafish

We use zebrafish to explore how genes work in various diseases with different genetically modified lines to help researchers pinpoint the precise effects of genetic changes. We use guppies to understand how new organs are created by studying the placenta.

Chicken eggs

We use fertilised chicken eggs to study development – another example where embryos develop outside the body – and to incubate flu viruses for the World Health Organization Worldwide Influenza Centre

Caring for our animals

Caring for our animals

We strive to keep our animals as comfortable as possible and minimise their suffering. 

Teams of animal technologists and Named Animal Care and Welfare Officers (NACWOs) care for the animals and support researchers with their experiments, to minimise distress or adverse effects of procedures on animals. 

Named Veterinary Surgeons provide healthcare support 24 hours a day, seven days a week. We perform regular microbiological screening to closely monitor the health status of our animals.

Before they can conduct any experiments, everyone working with animals goes through extensive training, covering everything from legislation to hands-on animal handling. This ensures that they can perform the techniques correctly without causing unnecessary distress.

To keep their environments comfortable and interesting, we give our animals various enrichment materials. We regularly trial new enrichment materials to improve the animals' environments and keep up with the needs of science and industry developments.