What is the active coloring agent in hematoxylin?

Hematoxylin is a dye derived from the logwood tree and is commonly utilized in histopathology for its ability to stain cell nuclei. The active coloring agent in hematoxylin is hematein. Hematein is produced when hematoxylin undergoes oxidation, which enhances its staining properties, particularly its affinity for nucleic acids. This makes it effective for highlighting nuclei in tissue sections, providing good contrast against the cytoplasm, which is typically stained with another dye, such as eosin.

In histopathology, this combination (hematoxylin and eosin, or H&E) is fundamental for microscopic examination of tissue. Hematein’s mechanism as an active agent involves binding to DNA and RNA, which are abundant in the cellular nucleus. Thus, the choice of hematein as the active coloring agent illustrates key principles of histological staining techniques, underscoring the relevance of understanding the components of staining solutions in the context of tissue analysis.