Localization of Melanoma-associated Antigen P97 in Cultured Human Melanoma, As Visualized by Light and Electron Microscopy

The expression of a human melanoma-associated antigen, p97, in cultured melanoma cells was investigated using a modification of the Sternberger peroxidase-antiperoxidase (PAP) technique. Explant cultures of two skin melanomas were found to consist of a mixture of cells, some positive and some negative, for the expression of p97. From two other melanomas two cell lines were newly established. All cells from these lines expressed detectable p97 over a period up to 18 months. With the cell lines and the explant cultures we have initiated an investigation of the expression of p97 at the ultrastructural level, using the PAP technique. Antigen expression was detected as a continuous, strongly stained band at the cell surface of the melanoma cells.