The 3R principle
The 3R principle reflects responsible scientific practice: reducing the number of animal experiments and minimizing animal suffering both strengthen animal welfare and support reliable research outcomes.
What is the 3R principle?
1. Replace
Replace animal testing with alternatives whenever possible
At LMU and the University Hospital, parts of animal experimentation have long been replaced by the use of organoids or tumor spheroids in research. In the education of veterinary and human medicine students, increasing use is made of dummies and teaching videos. In human medical training, the use of animals can now be completely avoided.
2. Reduce
Reduce the number of animals to the minimum necessary.
At LMU and the University Hospital, modern imaging techniques such as intravital microscopy, MRI, CT, and catheter-based methods are regularly employed in research. These allow the same animal to be examined repeatedly at different points of time – for example during different stages of disease or recovery –thereby reducing the number of animals needed while producing more precise and comparable results. With the newly opened Interdisciplinary Center for Advanced Imaging and Intervention (ICON), LMU and the University Hospital are further consolidating their expertise in these innovative imaging and interventional techniques.
3. Refine
Refine procedures to minimize pain, suffering, and stress.
At LMU and the University Hospital, great importance is placed on high standards of animal housing and the use of particularly gentle experimental methods. Housing practices also include tunnel handling and training methods that encourage voluntary participation by the animals. A
Animals in experiments are carefully monitored – sometimes several times a day – for signs of distress, so that appropriate measures, such as timely treatment of any pain, can be taken at an early stage.
The 3R principle at LMU and the University Hospital
At LMU and the University Hospital, researchers and animal care staff are jointly committed to the consistent implementation of the 3R principle. In all research projects involving animal experiments, they strive to improve the welfare of laboratory animals while enhancing the quality of scientific research.
We're driving change: Examples of the 3Rs at LMU and the University Hospital
Using cell- and genomics-based approaches, we make developmental and regenerative processes visible. For example, we study human tissues and other patient-derived and healthy volunteer samples to identify biomarkers through omics analyses – only with the appropriate ethical approval of course.
Organs grown in the lab – such as miniature versions of bone marrow – closely replicate complex tissues in a realistic way and open up new possibilities for testing.
- Dr. von Hauner Children's Hospital: Organoid Lab
- NIH: Optimized Adeno-Associated Virus Vectors for Efficient Transduction of Human Retinal Organoids
- Doctoral dissertation: Tumor-immune-interaction in a pancreatic cancer organoid co-culture model
Targeting treatment-resistant tumors: new therapeutic approaches combined with patient-relevant 3D models that allow faster and more realistic testing of efficacy.
Building tissues in a targeted way: bioprinting and microfluidics create controlled in vitro systems for research and testing.
Realistic practice without animals: an equine rectal examination model improves skills, safety, and training practice.