Legal requirements and the 4Rs principle

German animal welfare legislation is one of the strictest in the world. In addition, we are committed to the 3R principle (Replacement, Reduction, Refinement) and the fourth R of the Max Planck Society which stands for Responsibility.

Approval of animal experiments

Working with animals gives rise to a great ethical responsibility, which both the Institute and the individual scientists take very seriously. All experiments are carefully planned. Every animal experiment must be justified and described in detail. The expected scientific benefit must be weighed against the burden on each individual animal. An extensive literature search must clarify in advance whether the planned experiment has not already been carried out elsewhere and would therefore be dispensable (3R principle). Only after this preliminary work can the animal experiment be applied for.

When deciding on the approval or rejection of an animal experiment application, the authority is supported in an advisory capacity by a commission according to §15 of the Animal Welfare Act, which deals intensively with each application. This commission includes members with basic expertise in animal experimentation as well as representatives from proposal lists of animal welfare organisations.

Animal experiments present scientists with an ethical dilemma: on the one hand, they try to create new knowledge, and on the other hand, they have to resort to animal experiments in which the animals may suffer pain or distress. There is no satisfactory solution to this conflict, as studies on animals are often the only way to gain knowledge about processes in nature.

That is why the best possible husbandry conditions and responsible treatment of animals are an ethical obligation for research projects. The researchers are concerned to keep the number of animal experiments as well as the stress on the animals in the individual experiments as low as possible. They apply the so-called 3Rs principle when planning and carrying out the experiments. In addition, veterinarians, qualified animal caretakers and animal welfare officers ensure that all the necessary conditions are in place for the welfare of the animals.

The 3Rs principle

The 3Rs "Replacement, Reduction, Refinement" are the basis for planning and conducting all experiments with animals at the Institute. The terms were coined by two British researchers, the zoologist William Russell and the microbiologist Rex Burch, and published in 1959 in their book  „The Principles of Humane Experimental Technique” as a principle of experimental scientific work.

The aim of the 3Rs principle is to avoid animal experiments wherever possible, to reduce the number of animals and to limit the suffering of laboratory animals to an indispensable level. The 3Rs Principle is a legal requirement (2010/63/EU) and at the same time an ethical obligation (White Paper), that all employees at MPI-IE who are involved in animal experiments follow.


An animal experiment may only be carried out if there is no suitable alternative method to answer the research question. The aim is therefore to find other possibilities for the animal experiment before the experiment begins, if possible. This usually includes not only experiments in cell cultures (in vitro tests) but also the use of computer simulations. The use of other organisms such as fruit flies (D. melanogaster) or worms (C. elegans) can also help to replace animal experiments with more highly developed and sensitive organisms for certain questions.


The number of laboratory animals is reduced as much as possible. This begins with optimal housing conditions and species-appropriate handling of the animals in order to produce reliable results and avoid having to repeat experiments. At the same time, clever study design and good study evaluation help to ensure that even with the smallest possible number of animals and experiments, statistically reliable results are still produced. The use of imaging techniques can also help to reduce animal experiments by allowing the animals to be examined more gently and repeatedly (e.g. to check tumour growth).


In order to minimise the stress on the animals during the experiments, methods and husbandry are constantly being improved with regard to the latest findings. For example, new handling methods cause less stress to mice when they are lifted out of the cages with the help of tubes (tunnel handling) aus den Käfigen gehoben werden.

In the experiments, the focus is always on choosing the most gentle gentlest experimental method, using the shortest possible experiments and consistently treating any pain that occurs. In refinement, too, imaging techniques make it possible to conduct more gentler experiments to create images and videos of the inside of the body without having to perform operations surgeries or end the life of an experimental animal.


The fourth R - Responsibility

In addition, the Max Planck Society commits to a fourth "R" for Responsibility in a policy statement (White Paper – Animal Research in the Max Planck Society, 2016) As researchers in the MPG, we see ourselves as having a special responsibility to put our broad scientific know-how at the service of animal welfare and, at the same time, to further improve the quality of research. For us, this means not only ensuring the highest quality standards in animal husbandry and animal experimentation projects, but also actively supporting the Max Planck Society's measures and programmes to promote animal welfare in biomedical research. The fourth R also includes participation in the ethical discourse in public on the subject of animal experimentation, which we aim to conduct on a professional basis.



Legal Basis & Regulatory Information

Directive 2010/63/EU of the European Parliament and of the Council of 22 September 2010 on the protection of animals used for scientific purposes. With Directive 2010/63/EU, the EU is implementing the principle of "Replace, Reduce, Refine (3Rs) across Europe.

The German Animal Welfare Act (German only)The purpose of this law is to protect the life and well-being of animals out of man's responsibility for them as fellow creatures". (§1 TierSchG)

Ordinance on the Protection of Experimental Animals (German only) (TierSchVersV) Ordinance on the protection of animals used for experimental and other scientific purposes.

German Centre for the Protection of Laboratory Animals (Bf3R) coordinates all activities, nationwide to limit animal experiments to the indispensable minimum and to provide laboratory animals with the best possible protection.

AnimalTestInfo Database on animal experimentation projects in Germany provided by the Bf3R. Approved animal experimentation projects are published anonymously with generally comprehensible project summaries.

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