Specificity and Comments:
HMB45 reacts with a neuraminidase-sensitive oligosaccharide side chain of a
glycoconjugate present in immature melanosomes. The HMB45-reactive antigen is
present in cutaneous melanocytes, prenatal and infantile retinal pigment
epithelium (RPE), and melanoma cells and is thought to be oncofetal in nature.
This antibody has been shown to label the majority of melanomas.
Normal cells: The antibody reacts with junctional and blue nevus cells and,
variably, with fetal and neonatal melanocytes. Intradermal nevi and normal adult
melanocytes are negative. Non-melanocytic cells are negative.
Tumor cells: This antibody reacts with the majority of melanomas and other
tumors showing melanoma/melanocytic differentiation, including melanocytic
schwannoma clear cell sarcoma. In general, “epitheloid” melanoma cells show more
uniform staining than more sarcomatous spindle-shaped melanoma cells. Tumor
cells of epithelial, lymphoid, glial and mesenchymal origin are negative.
Species Reactivity: Human; others-not tested.
Extract of pigmented melanoma metastases in lymph nodes.
Known Applications: Immunohistochemistry
(formalin-fixed paraffin-embedded tissues)
Positive Control: Melanoma
Buffer with protein carrier and preservative
Storage and Stability:
Store vial at 4°C. Stable for 18 months.