Hematoxylin is widely used in histology and pathology for staining tissues, particularly in the preparation of microscope slides. It binds to cell nuclei, turning them a distinct blue or purple color, which helps in visualizing cellular structures under a microscope. This staining is essential for diagnosing diseases, as it allows pathologists to examine tissue samples for abnormalities, such as cancerous cells or infections. Hematoxylin is often paired with eosin (H&E staining) to provide a comprehensive view of both nuclear and cytoplasmic details. Its application is critical in medical research, clinical diagnostics, and educational settings for studying tissue morphology and disease progression.