Iron hematoxylin is primarily used for what purpose?

Iron hematoxylin is primarily used for differential staining because it selectively stains various cellular components, particularly nuclei and certain cytoplasmic structures. Its ability to differentially stain allows for the identification of specific cell types and other histological features in tissue samples. This technique is valuable in histopathology, as it aids in distinguishing between different types of cells and their components, which is crucial for accurate diagnosis and evaluation of tissue pathology.

In practice, iron hematoxylin binds to nucleic acids, imparting a dark blue to black color to the nuclei and providing contrast with the surrounding tissues and other cell types, thus facilitating the differentiation between them. This enhanced visualization is essential for pathologists when assessing the morphology and cellularity of diseased tissues.

While the other options relate to staining, they do not fully capture the primary use of iron hematoxylin. It is not exclusively for staining nucleic acids, nor is it specifically designed to highlight connective tissues or stain background elements, which are generally achieved through other techniques or staining protocols.