Diff-Quik is a Romanowsky-type stain.

• A. Diff-Quik
• B. Pap
• C. H&E
• D. Gram

Answer: (A)

Diff-Quik belongs to the group of Romanowsky-type stains, which work by combining basic and acidic dyes to create a multichromatic stain. This approach highlights nuclei in blue to purple and cytoplasmic elements in pink to orange, making cellular details easy to distinguish in smear preparations. Diff-Quik is a rapid, modified Wright-Giemsa method derived from that staining family, commonly used for cytology smears and quick assessments. The Pap stain is Papanicolaou, a different cytology stain with its own multi-step protocol, not classified as Romanowsky-type. Hematoxylin and eosin is the standard tissue-staining combo for histology, coloring nuclei blue and cytoplasm pink, again not a Romanowsky-type. Gram staining is a bacterial differential stain, not part of the Romanowsky family. So, Diff-Quik is the Romanowsky-type stain.