What type of cellular material does hematoxylin primarily stain?

Hematoxylin primarily stains cell nuclei due to its affinity for nucleic acids, particularly the DNA and RNA found within these structures. The stains interact with the negatively charged phosphate groups of nucleic acids, resulting in a characteristic blue to purple coloration that helps to visualize the nuclear components under a microscope. This property makes hematoxylin an essential dye in histopathology, as it highlights nuclear details and allows for the identification and assessment of various cellular conditions and abnormalities.

In histological preparations, the clear distinction of the nuclei from the surrounding cytoplasm and extracellular matrix is crucial for diagnosing diseases, studying tissue architecture, and understanding cellular behavior. Other cellular components, such as collagen fibers or cytoplasm, do not exhibit the same affinity for hematoxylin, hence leading to a lack of significant staining in those areas. While the extracellular fluid may also not show any staining, the primary role of hematoxylin remains focused on the nuclei, making it a vital stain in histological techniques.