3Rs Principle: Replace, Reduce, Refine

Wherever possible, research using animals should be replaced with methods that do not involve animals. The number of animals in a study should be kept as low as possible without reducing statistical significance. And the stress caused to animals should be reduced as far as possible by improving experimental procedures and conditions. Replace, reduce, refine – these are the guiding principles of the 3Rs principle.

LASC
LASC
Since mice are the most frequently used animals in research, the 3Rs principle is particularly effective here. (Image: Frank Brüderli, UZH)

The 3Rs principles are based on the 1959 Principles of Humane Experimental Technique by William Russell and Rex Burch. The principles are the internationally established guidelines for ethical treatment of animals in research. The 3Rs principle aims to avoid or reduce animal testing and the animals’ suffering.

Replace Replace the animal experiment with a procedure that does not involve animals
Reduce  Reduce the number of animals to the required minimum
Refine  Refine the experimental procedures and conditions to minimize distress and promote animal welfare

UZH has had a 3R coordinator since April 2018. The role involves promoting 3Rs research and advising and training students, scientists and animal caretakers on relevant topics. The 3R coordinator also represents UZH at the Swiss 3R Competence Center.