What is the primary staining method used for routine histopathological examination?

Hematoxylin and eosin (H&E) staining is the primary staining method used for routine histopathological examination due to its effectiveness in highlighting cellular structures and tissue organization. H&E provides a clear contrast between different tissue components; hematoxylin stains nuclei blue or purple by binding to DNA and RNA, indicating active cellular processes, while eosin stains the cytoplasm and extracellular matrix in shades of pink, allowing for visualization of overall tissue morphology.

This dual staining method is foundational in histopathology as it enables pathologists to assess cellular architecture, identify specific tissue types, and recognize abnormalities such as inflammation, neoplasia, and other pathological changes. H&E staining is typically the first step in the examination of tissue samples, serving as a vital tool in diagnosing various diseases and conditions.

Other staining methods mentioned serve specific purposes but are secondary to H&E in routine histopathological assessments. Immunohistochemistry is used for detecting specific antigens in tissues, Masson's trichrome stain is utilized for differentiating collagen from other tissue components, and Giemsa stain is primarily applied in hematology for blood smears and certain cytological samples. While valuable, these techniques are often used after initial H&E evaluation to provide further insights or