Which stain can differentiate between fats and other cellular components?

Osmic acid is the correct choice for differentiating between fats and other cellular components due to its specific ability to bind to lipids. When tissues are treated with osmic acid, lipids undergo a process called osmic fixation, where the unsaturated bonds in fats react with the osmic acid, resulting in the formation of a black precipitate. This characteristic darkening allows for clear visualization of fat globules in tissue sections under a microscope.

Hematoxylin primarily stains nucleic acids, highlighting cell nuclei and providing no distinction between fats or other components. Acridine orange is a fluorescent dye that intercalates with nucleic acids and is used mainly for detecting RNA and DNA, not for differentiating fats. Orcein is used to stain elastic fibers and some other components, but it does not have the specificity for lipids that osmic acid provides. Thus, osmic acid is uniquely suited for the task of differentiating fats, making it the most appropriate choice among the options.