Which stain is used as the second counterstain in Pap smear?

Which stain is used as the second counterstain in Pap smear?

• A. Harris hematoxylin
• B. OG 6 stain
• C. EA 50 stain
• D. Papanicolaou

Answer: (C)

Pap smear staining relies on layering colors to distinguish nuclei from cytoplasm. After staining the nuclei with Harris hematoxylin, the first cytoplasmic counterstain is Orange G, which gives the cytoplasm an orange hue in certain cell types. The second counterstain, EA-50 (eosin azure), provides a blue-green tint to the cytoplasm of non-keratinized cells and other structures, enhancing nuclear-cytoplasmic contrast and helping differentiate cell types on the slide. The stain is named after the overall Papanicolaou method, not a single dye, and the primary nuclear stain is Harris hematoxylin; OG-6 is the first counterstain, while EA-50 is used as the second.

Pap smear staining relies on layering colors to distinguish nuclei from cytoplasm. After staining the nuclei with Harris hematoxylin, the first cytoplasmic counterstain is Orange G, which gives the cytoplasm an orange hue in certain cell types. The second counterstain, EA-50 (eosin azure), provides a blue-green tint to the cytoplasm of non-keratinized cells and other structures, enhancing nuclear-cytoplasmic contrast and helping differentiate cell types on the slide. The stain is named after the overall Papanicolaou method, not a single dye, and the primary nuclear stain is Harris hematoxylin; OG-6 is the first counterstain, while EA-50 is used as the second.