Formalin-fixed, paraffin-embedded human Melanoma stained with gp100 / Melanosome Monoclonal Antibody (HMB45 + PMEL/783).
Formalin-fixed, paraffin-embedded human Testis stained with gp100 / Melanosome Monoclonal Antibody (HMB45 + PMEL/783).
Western Blot Analysis of COLO-38 cell lysate using gp100 / Melanosome MAb (HMB45 + PMEL/783).
Known Applications & Suggested Dilutions
Host / Ig Isotype
Mol. Weight of Antigen
Specificity & Comments
The gp100 molecule is a 100kDa glycosylated protein that is cleaved into a small (26kDa) carboxy-terminal fragment and a larger amino- terminal section (60-64 kDa), which is subsequently cleaved to generate 26kDa and 34-38kDa. By immunohistochemistry, it specifically recognizes a protein in melanocytes and melanomas. This MAb reacts with junctional and blue nevus cells and variably with fetal and neonatal melanocytes. Intradermal nevi, normal adult melanocytes, and non-melanocytic cells are negative. It does not stain tumor cells of epithelial, lymphoid, glial, or mesenchymal origin. Metastatic amelanotic melanoma can often be confused with a variety of poorly differentiated carcinomas, large cell lymphomas, and sarcomas using H E stains alone. It is also difficult to differentiate melanoma from spindle cell carcinomas and various types of mesenchymal neoplasms. This MAb stains fetal and neonatal melanocytes, junctional and blue nevus cells, and malignant melanoma. This MAb also stains Angiomyolipoma (PEComa).