[How to handle unkown fluids in fluid-preserved collections : Cloudy prospects?].

Background: Fluid collections are gaining more importance for research and teaching, but they are facing preservation problems. In the case of historical collections, the methods of fixation and preservation are poorly documented. The liquid used is unknown. In order to ensure the preservation of such collections, it is essential to have available a preservation liquid that is compatible with the most common historical liquids and techniques.

Materials And Methods: A universal liquid based on historical recipes was developed for such problematic preparations.

Results: The use of distilled water, glycerin and ethanol (80%) in a ratio of 10:6:1 offers a good alternative that is harmless to the health of the user. It can be used for colour-preserving conserved preparations and for pure ethanol and formaldehyde preparations and is recommended as a universal solution for preparations in unknown preservation liquids.