3Rs methods

Responsible use of laboratory animals entails checking which methods for Replacement, Reduction and Refinement (3R-methods) are available. Information can be obtained via literature research, searchable databases and informative websites.


Some revolutionary developments are currently being made in the field of in-vitro methods. Examples are an organoid (cultured cells in 3d), a body-on-a-chip (cultured cells on a computer chip). This allows the study of cells interacting with each other or substances. This method is an effective way of replicating organ systems for scientific research. Think in advance whether you can replace (parts of) your animal experiments. For example, search the NAT database or ask your question at the TPI Utrecht Helpdesk (Utrecht Transition Programme for Innovation without the use of animals Helpdesk).


Whether the discomfort involved is minor or severe, it is always better to expose as few animals as possible to discomfort. However, the number of animals must be sufficient to draw reliable conclusions from the research. To balance these two interests, it is vital that the experiment is set up in a proper manner. This can be done by properly utilising statistical methods to obtain significant results with as few animals as possible, by choosing the right experimental model and by smart breeding techniques to ensure that as few 'surplus' animals as possible are bred. Ethical considerations (does the importance of the research justify the harm to the animals' welfare?) and accurately publishing methods and results are also vital elements in reducing the number of animals.


Another method for responsibly dealing with animal experiments is to alleviate pain or stress to minimise the harm to their welfare. This can be done by influencing their consciousness or experience of pain through anaesthetics or analgesics, but also by ensuring proper accommodation, experiment procedures and attention to the animals' behaviour. Other factors that affect the animals' welfare are the knowledge and experience of the people who work with the animal.

Need advice?

If you would like advice about 3R-methods, please feel free to contact either us or our partner, the 3Rs Centre.