Stain not used for lipids?
**Core Concept**
The question targets the principle of histological staining and its applications in identifying various cellular components, including lipids. In histopathology, specific stains are employed to highlight particular cellular structures or substances, facilitating diagnosis and disease characterization.
**Why the Correct Answer is Right**
Lipids are hydrophobic molecules that do not readily bind to water-based stains. The correct stain not used for lipids is Sudan III, which is specifically used to stain lipids in histological preparations. Sudan III works by binding to the lipid molecules, making them visible under a microscope. This is in contrast to other stains like hematoxylin and eosin (H&E), which are used to stain a wide range of cellular components but not lipids.
**Why Each Wrong Option is Incorrect**
**Option A:** Hematoxylin is used in H&E staining, which is a general-purpose stain for histology, but it is not specific for lipids.
**Option B:** Oil Red O is actually used to stain lipids, making it an incorrect option.
**Option C:** Alcian blue is used to stain mucins and glycosaminoglycans, which are not lipids.
**Clinical Pearl / High-Yield Fact**
When performing histological staining, it is essential to choose the correct stain for the specific cellular component of interest, as using the wrong stain can lead to incorrect diagnoses.
**Correct Answer: B. Oil Red O is used to stain lipids.**