Zeta’s mouse monoclonal antibodies recognize Melan-A (MART-1). MART-1 (Melanoma Antigen Recognized by T cells 1) or Melan-A1 is a newly identified melanocyte differentiation antigen recognized by autologous cytotoxic T lymphocytes. Melan-A/MART-1 is present in melanosomes and endoplasmic reticulum. Melan-A (MART-1) Clone 103 does not cross-react with MAGE-1 or tyrosinase protein. Melan-A (MART-1) Clone 103 labels melanomas and other tumors showing melanocytic differentiation. The antibody to Melan-A (MART-1) does not stain tumor cells of epithelial, lymphoid, glial, or mesenchymal origin.