Research Involving Animals – Division of Biomedical Services

The 3Rs

First defined back in 1959, the 3Rs are guiding principles for animal research used across the globe. They underpin policies, regulations and laws in the UK and many other countries.


Replacement is the use of techniques which does not involve animals. This includes scientific and technological developments, such as computer modelling. It also includes the use of human volunteers and research using cells and tissues. The use of invertebrates such as fruit flies (Drosophila) and nematode worms, instead of higher animals also comes into this category, as it is not currently thought that these simple creatures can experience suffering.


Refinement is the development of processes that decrease the stress or suffering of animals. This includes not only experimental techniques but also the care, feeding, housing and welfare of animals in facilities. Examples include finding the best anaesthetic for each species or simply getting animals used to being handled.


Reduction involves minimising the number of animals used through efficient experiment design. For example, taking repeated samples from one animal throughout a process (if this does not increase the animal’s suffering) rather than euthanising a series of animals at different stages of the process. Collaboration and sharing of data also contribute to reduction.


NC3Rs (National Centre for the Replacement, Refinement and Reduction of Animals in Research) supports the implementation of these principles and provides more detailed information about what each involves. As well as providing a training video for scientists, technicians, students and others involved in animal research.

The 3Rs working group 

The Division of Biomedical Services and associated researchers are actively identifying 3Rs (replacement, refinement and reduction of animals in research) related issues and implementing solutions. These efforts benefit from a co-ordinated approach towards the following:

  • Provide a forum for raising in-house 3Rs related issues and working as a group to find a solution
  • Act as a hub for sharing existing 3Rs approaches from external sources and consider local implementation
  • Act as an audience for new 3Rs ideas, exploring feasibility and providing support in the validation and evaluation of any initiatives
  • Disseminate local 3Rs successes via the website

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