Which reagents are used in the Eosin Phloxine B staining protocol?

• A. Eosin Y, Phloxine B, 95% Ethanol, GAA
• B. Hematoxylin, Eosin Y, 70% Ethanol
• C. Methylene blue and Azure A
• D. Acetic acid and water

Answer: (A)

The main idea is identifying the exact components used in the Eosin Phloxine B staining protocol. This method relies on two acidic dyes, Eosin Y and Phloxine B, to produce the characteristic pink-to-red cytoplasmic staining, and it is combined with a dehydration and acidification system to optimize dye uptake and tissue preservation. The reagents typically listed for this protocol are Eosin Y, Phloxine B, 95% Ethanol for dehydration, and glacial acetic acid (GAA) to acidify the staining medium and help the dyes interact with the tissue.

Why this set is the best fit: Eosin Y and Phloxine B are the dyes that give the distinct staining pattern of the eosinophilic components. The 95% ethanol is essential to dehydrate and prepare the tissue so the dyes can penetrate consistently. The glacial acetic acid adjusts the pH to enhance dye uptake and contrast, which is a key feature of this specific staining protocol.

Why the other options don’t fit: Hematoxylin is a nuclear stain used in combination with eosin in H&E, not part of this eosin–phloxine scheme. Methylene blue and Azure A belong to different staining systems and are not used together for Eosin Phloxine B. Acetic acid and water alone do not provide the dye components or the dehydration step necessary for this protocol.

In short, the correct combination pairs the two dyes with the appropriate dehydration and acidification components to achieve the Eosin Phloxine B staining results.