What are the 3Rs?
The 3Rs are a guiding principle to foster ethical use of animals in scientific and educational experiments. The 3Rs stand for:
Replacement uses alternative methods which either avoid or replace the use of animals in experiments. For example, the use of human-cells and tissue cultures or computer modelling.
Reduction is done when methods are applied that result in the use of a smaller number of experimental animals or that provide more information from the same number of animals. For example, statistical methods accurately calculate the number of animals that is needed for a scientifically valid study.
Refinement becomes very important when the use of animals cannot be avoided. Animal welfare becomes then a high priority. Any stress, pain and suffering inflicted should be kept to a minimum. It can for example be a simple measure such as respecting the natural day/night cycle of the animal, but also the use of suitable analgesics, anaesthetics.
Alternatives for today and the near future
Promoting scientific research that benefits human health while improving animal welfare: yes, it is possible!
What are alternative methods? NAMs?
In vitro methods
These are testing methods on biological matter, conducted outside of a living organism and in a controlled environment like for example cells or tissue cultures obtained from repositories and cultured to create the necessary model (e.g. reconstructed human epidermis).
Ex vivo methods
These are also testing methods on biological matter, but for which the cells and tissues are taken from a living organism, whether donated or harvested such as hair follicles, skin explants.
In silico methods
Refer to the use of computational approaches such as prediction models or simulations run on a computer. Often used are grouping, read across and other methodology for which the quality of the databases used is very important.
In chemico methods
Do not use any human or animal cells, but evaluate how a chemical interacts with certain materials. A typical example is the DPRA (Direct Peptide Reactivity Assay), which is a test to assess the skin sensitisation potential of chemical substances.
In vivo experiments
There are also still some in vivo experiments with invertebrates (e.g. fruit flies and flatworms). Because of their low level of consciousness, invertebrates are seen as less able to experience psychological distress. Therefore, current European legislation (Directive 2010/63/EU) does not define invertebrates (except for cephalopods) as laboratory animals.