Used in histology laboratories to differentiate stained tissue sections, particularly in the Hematoxylin and Eosin (H&E) staining procedure. It helps remove excess stain from tissue samples, allowing for clearer distinction between cell nuclei and cytoplasm. By controlling the rate and extent of de-staining, it enhances the contrast and specificity of microscopic features, ensuring accurate tissue analysis. Commonly used after hematoxylin staining to achieve optimal nuclear clarity before proceeding to counterstaining steps. Its effectiveness depends on the concentration and duration of exposure, making it a critical step in diagnostic pathology.