Romanowsky-type stains are best described as combinations of which dye types?

• A. Acid and basic dyes
• B. Only basic dyes
• C. Only acidic dyes
• D. Neutral dyes

Answer: (A)

Romanowsky-type stains rely on a two-dye system: a basic dye and an acidic dye. The basic dye binds to negatively charged cellular components like nucleic acids in the nucleus, staining them blue to purple, while the acidic dye binds to positively charged components such as cytoplasmic proteins, giving pink to red hues. Using both types together creates the characteristic multicolored appearance that helps differentiate cellular structures in blood smears and bone marrow samples. Neutral dyes aren’t part of this scheme, and using only one type wouldn’t provide the same range of colors.