Which statement best describes the color of nuclei after H&E staining?

• A. Blue
• B. Red
• C. Green
• D. Yellow

Answer: (A)

In H&E staining, the nucleus appears blue because the hematoxylin component is a basic dye that binds to acidic, or basophilic, structures in the nucleus such as DNA and RNA. This creates the characteristic blue to purple coloration of nuclei, providing contrast to the cytoplasm which is stained pink by the eosin counterstain. The pink or red colors described by the other options come from eosin staining of cytoplasmic proteins, not from the nuclei. So the best description is blue for the nuclei after H&E staining.