Description: This antibody recognizes a protein doublet of 20-22 kDa, identified as MART-1 (Melanoma Antigen Recognized by T cells - 1) or Melan-A. MART-1 is a melanocyte differentiation antigen recognized by autologous cytotoxic T lymphocytes. MART-1 is present in melanosomes and endoplasmic reticulum. It does not stain tumor cells of epithelial, lymphoid, glial, or mesenchymal origin. This antibody is a useful marker for identification of metastatic melanomas.