Which stain is utilized for identifying both triglycerides and cholesterol?

The choice of Sudan III as the stain utilized for identifying both triglycerides and cholesterol is based on its specific properties as a lipid-soluble dye. Sudan III is known for its ability to stain neutral lipids, which include triglycerides and cholesterol. When tissue or fluid samples are exposed to this stain, any triglycerides or cholesterol present will take on a reddish-orange hue, allowing for clear identification under a microscope.

This staining method is particularly useful in clinical settings, such as in the analysis of urine or body fluids, where the presence of lipids can indicate various metabolic conditions or diseases. The clear differentiation provided by Sudan III facilitates the diagnosis and evaluation of lipid-related pathologies.

Other stains mentioned in the options have different applications. For instance, Prussian blue is primarily used for identifying iron deposits in tissue, the Gram stain is used to classify bacteria based on their cell wall structure, and the Steihimer-Malbin stain is specifically designed for identifying certain types of cells, particularly in hematology. Thus, these stains are not suitable for detecting both triglycerides and cholesterol as Sudan III can.