Which technique demonstrates both alpha and beta cells in the pancreatic islet of Langerhans?

• A. Gomori method
• B. Hematoxylin and eosin
• C. Periodic acid-Schiff
• D. Masson's trichrome

Answer: (A)

Staining endocrine pancreatic islets to distinguish alpha and beta cells relies on staining the secretory granules inside these cells. Gomori’s aldehyde fuchsin technique highlights the hormone-containing granules within islet cells, making both alpha and beta cells visible within the islet. The granules in beta cells (insulin-containing) stain prominently, and alpha cells (glucagon-containing) show contrasting granules as well, allowing their coexistence to be demonstrated in the same field. The other stains don’t target these granules specifically: hematoxylin and eosin gives general tissue morphology but doesn’t reliably differentiate alpha from beta cells; periodic acid–Schiff marks carbohydrates and is not specific to endocrine granules; Masson’s trichrome emphasizes connective tissue and muscle fibers rather than islet endocrine granules.