Hematoxylin and eosin (H&E) is a widely used staining technique in histology, the study of tissues. Hematoxylin stains cell nuclei blue, highlighting DNA and RNA, while eosin stains the cytoplasm and extracellular matrix pink. This contrast allows for clear visualization of tissue structures under a microscope. The H&E stain is essential for diagnosing diseases, particularly in pathology. It helps pathologists identify abnormal cells and tissue changes, aiding in the detection of conditions like cancer. The simplicity and effectiveness of H&E make it a standard method in laboratories worldwide.