The 0.01% toluidine blue solution is based on an aqueous base and contains toluidine blue (C.I.: 52040) as the central dye. Applications of this solution are in histology and cytology, where it is used to identify acidic polysaccharides, glycoproteins and mast cells.

Chemically, toluidine blue binds selectively to acidic components of tissue. Interaction with acidic groups in polysaccharides and glycoproteins results in differential staining that allows differentiation of these structures. With regard to metachromatic properties, the dye reacts with heparin in mast cells, resulting in a color change.

The special suitability of the 0.01% toluidine blue solution is demonstrated in various microscopic examination methods, especially in the visualization of cartilage tissue, mucus and basophilic substances. In cytology, the solution is used for evaluation of cell smears and detection of mast cells. With the help of toluidine blue solution, detailed information about the examined tissues and cells can be obtained, which is important for the diagnosis and understanding of diseases.