Staining chemicals enhance the contrast of tissue sections, making cellular components distinguishable under a microscope. There are various types of stains, each targeting specific cellular structures: 1. Hematoxylin and Eosin (H&E) stain: Hematoxylin stains nuclei blue-purple, while eosin stains cytoplasm and extracellular matrix pink. This is the most common staining technique. 2. Periodic Acid-Schiff (PAS) stain: This stains carbohydrates and mucin, highlighting structures like basement membranes and glycogen. 3. Trichrome stains: These differentiate between muscle fibers, collagen, and fibrin, often used in liver and kidney biopsies.
