Which product stains fat?

Which product stains fat?

• A. Sudan III or IV
• B. New methylene blue
• C. Diff-Quik
• D. Giemsa

Answer: (A)

Staining fats relies on lipid-soluble dyes that partition into lipid droplets, making fats visible under the microscope. Sudan III and Sudan IV are classic lipid stains; they dissolve in fats and color neutral fats orange-red, so fat-rich tissues light up distinctly. The other stains are general cellular dyes: New methylene blue binds to acidic structures like nucleic acids and highlights nuclei and basophilic components, while Diff-Quik and Giemsa are Romanowsky-type stains designed to differentiate cell types in blood smears and cytology, emphasizing cytoplasm, nuclei, and bacteria rather than fats. So, for visualizing fat, the Sudan dyes are the best choice.

Staining fats relies on lipid-soluble dyes that partition into lipid droplets, making fats visible under the microscope. Sudan III and Sudan IV are classic lipid stains; they dissolve in fats and color neutral fats orange-red, so fat-rich tissues light up distinctly. The other stains are general cellular dyes: New methylene blue binds to acidic structures like nucleic acids and highlights nuclei and basophilic components, while Diff-Quik and Giemsa are Romanowsky-type stains designed to differentiate cell types in blood smears and cytology, emphasizing cytoplasm, nuclei, and bacteria rather than fats. So, for visualizing fat, the Sudan dyes are the best choice.