Hematoxylin and Eosin Stain, commonly known as H&E stain, is a widely used technique in histology for examining tissue samples. It involves two main dyes: hematoxylin, which stains cell nuclei blue, and eosin, which stains the cytoplasm and extracellular matrix pink. This contrast helps pathologists identify different cellular structures and assess tissue morphology. The H&E stain is essential for diagnosing diseases, including cancers, by allowing for the visualization of cellular details under a microscope. It is a standard procedure in laboratories and is often the first step in evaluating tissue biopsies for various medical conditions.