Which of the following is a primary use of Oil Red O staining?

Oil Red O staining is primarily used to detect and visualize lipids within tissues. This staining technique specifically highlights the presence of neutral lipids and triglycerides, allowing for the assessment of fat distribution in various types of tissues. It has significant applications in pathology, especially in the examination of adipose tissue, liver biopsies, and other organs where fat accumulation may be of interest, such as in cases of metabolic disorders or lipid storage diseases.

The dye binds to lipid droplets, resulting in a bright red color that makes the identification of fat deposits straightforward under a microscope. This characteristic is crucial for pathologists when diagnosing conditions that are related to lipid metabolism.

In contrast to other options, identifying bacterial infections would typically involve different stains such as Gram stain, while visualizing bone structures often requires special techniques like Masson's trichrome or Alizarin red stain. Highlighting cellular nuclei is more accurately performed with stains such as Hematoxylin, which binds to nucleic acids. Thus, the use of Oil Red O for determining fat distribution is distinct and essential in its specific application within histopathology.