The mixture of 1% hydrochloric acid and 70% isopropanol finds its use in histology and cytology, especially as a solution for differentiation and dehydration during staining of tissue samples. It enables sharp and precise visualization of cell structures and facilitates the detection of abnormalities.

The mixture is particularly suitable for staining methods such as hematoxylin-eosin staining, where it acts as a differentiation agent to remove excess dye and enable clear visualization of tissue structures. The use of hydrochloric acid in the mixture causes the formation of light and dark tones, which are important for distinguishing tissue types and morphological changes.

Chemically, the mixture has a number of properties that make it ideal for these applications. Hydrochloric acid, a strong acid, promotes differentiation by protonating the dye molecules, making them easier to remove from the tissue. Isopropanol, a secondary alcohol, acts as a dehydrating agent by removing water from the tissue, increasing the strength of cell structures. Together, these properties provide an effective medium for the preparation and staining of tissue samples.