Which stain is specifically used for identifying neutral lipids in cells?

Oil red O is the correct choice for identifying neutral lipids in cells. This particular stain is a fat-soluble dye that specifically binds to triglycerides and other neutral lipids within tissue sections. When tissues are treated with Oil red O, areas rich in lipid will appear bright red against a yellow background, allowing for clear visualization of lipid deposits. This property makes it particularly useful in histological examinations where the identification of fat storage and distribution within cells and tissues is required, such as in various metabolic diseases or in assessing the presence of lipids during pathological conditions.

Other stains mentioned, such as Sudan black stain and Mallory stain, also have roles in lipid detection, but Oil red O is the most widely recognized for its specificity to neutral lipids. Hematoxylin stain, on the other hand, is primarily used for staining cell nuclei and does not have an affinity for lipids. Thus, the unique characteristics of Oil red O make it the preferred choice for analyzing neutral lipids effectively in a histological context.