Eosin Y is a xanthene dye, an organobromine compound and a monocarboxylic acid used for the differential staining of connective tissue and cytoplasm. In histopathology, it is applied as a counterstain after hematoxylin and before methylene blue. It is also used as a background stain, thereby giving contrast to the nuclear stains.
Eosin is often employed in microscopy as a counterstain for visualizing proteins, connective tissues, fibers and keratin in sample material of human origin, and even for the routine staining of cryosections. According to user requirements, it can be used for the preparation of the commonly used aqueous or alcoholic Eosin Y staining solutions. This ready-to-use staining solution is mostly used for routine staining in the hematoxylin-eosin staining process (H&E). The H&E staining process is the most frequently used staining method for histological material. Hematoxylin solution stains the nuclei blue/dark violet in color and the Eosin Y solution imparts red-orange color to the cytoplasm and intercellular substances.
Correct usage of the solution results in various shades of pink to aid in visualization of tissue components, such as erythrocytes, collagen, and the cytoplasm of muscle or epithelial cells.
Cytoplasm: Pink to Red.
Erythrocytes: Pink to Red.
Applications:
Eosin Y has been used as a stain:
• to determine the location of the brain sections
• for staining of fixed liver tissue
• for histological examination of brain sections from the dorsal hippocampus
Molecular Formula: C20H8Br4O5
Molecular Weight: 647.9 g/mol
Synonyms: Eosin, Aizen eosine GH, Eosin Y, Red 21, Tetrabromofluorescein
CAS No.: 548-26-517372-87-1
MDL number: MFCD00036189
InChI key: AZXGXVQWEUFULR-UHFFFAOYSA-N
