Hematoxylin is widely used in histology and pathology for staining tissue samples. It is a key component in the hematoxylin and eosin (H&E) stain, which is the most common staining method in medical diagnostics. Hematoxylin binds to cell nuclei, staining them a deep blue or purple, allowing for the visualization of cellular structures under a microscope. This is crucial for identifying abnormalities in tissue samples, aiding in the diagnosis of diseases such as cancer. Additionally, it is used in botanical studies to stain plant tissues, helping researchers study plant cell structures. Its ability to provide clear contrast makes it indispensable in both medical and biological research.