Standardization in animals experiments

Today we would like to discuss about an important deal of experimental research: standardization procedure in animal experiments. Animal models are crucial to study human diseases but ethical problems concerning their use in lab are usually encountered. The US animal care and use regulations require scientists not to duplicate experiments previously performed in other labs, assuming that standardized procedures described in textbooks guarantee reproducibility between laboratories and make useless repetition.

These standardization procedures want to define environmental conditions in order to render animals homogeneous within an experiment and to improve comparability between labs. Is it possible to overcome all differences between labs? Can we obtain the same environmental conditions in winter or summer, for instance? Moreover, animals are sensible to noise, to room architecture and specially to the scientist that manipulate them. For this reason scientists often state in their publications that results only hold for the conditions under which the experiment has been carried out. In this case, generalization is not recommended and sometimes comparison with other works doesn’t make sense.
Other approaches to standardize experiments have to be proposed. We invite you to read an interesting paper in Nature Methods where authors proposed environmental heterogenization , a systematic way to control variation in experimental conditions. Good reading!