In Hematoxylin and Eosin stained sections, which color combination is correct for tissue components after staining?

• A. Nuclei blue; Collagen pink; Cytoplasm pink; RBCs dark pink
• B. Nuclei pink; Collagen blue; Cytoplasm blue; RBCs pink
• C. Nuclei blue; Collagen blue; Cytoplasm yellow; RBCs green
• D. Nuclei red; Collagen purple; Cytoplasm blue; RBCs red

Answer: (A)

The key idea is how hematoxylin and eosin dye different tissue components. Hematoxylin is a basic dye that binds strongly to nucleic acids, so nuclei appear blue or blue-purple. Eosin is an acidic dye that binds to proteins, staining cytoplasm, extracellular matrix like collagen, and red blood cells in pink to red hues. So the typical pattern is nuclei blue, with surrounding cytoplasm and collagen pink, and red blood cells also pink to dark pink due to hemoglobin.

The correct color combination reflects this: nuclei blue; collagen pink; cytoplasm pink; red blood cells pink/dark pink. This matches the standard appearance seen in routine H&E sections.