The picric acid-sublimate mixture is a fixative solution used in in vitro diagnostics to preserve tissue samples and prepare them for histological examination. The solution prevents cellular changes and tissue degradation by fixing and stabilizing protein structures. This preservation enables more accurate analysis of cell structures and morphology, which is essential for disease diagnosis and cell biology research. The combination of picric acid, sublimate and water creates an effective solution for tissue fixation.

The working principle of this picric acid-sublimate mixture is based on the ability of picric acid and mercury(II) chloride to bind to tissue or cell structures, thereby visualizing specific molecular components. Picric acid is a powerful fixative that denatures proteins by forming picrate compounds, rendering them insoluble. Mercury(II) chloride (sublimate) acts as an additional fixative, acting particularly on nucleic acids, lipids and polysaccharides. Thus, in in vitro diagnostics, the mixture helps stabilize, preserve and visualize tissue and cell structures while minimizing distortion and degradation.