Hemagglutination as an alternate technic for the detection of melanoma-specific cytoplasmic antigens

The extensive use of the single technic of immunofluorescence has resulted in the detection of an array of melanoma-specific antigens. Those antigens residing in the cytoplasm of the melanoma cell have been shown to cross-react across various melanoma cell lines in tissue culture, as well as across all fresh tumor cells isolated directly from patients. The ubiquitous nature of this antigenic activity, as defined by immunofluorescence, suggests that the presence of this activity may be important diagnostically. Isolation of one or more antigens from the cytoplasm, however, requires the development of an assay for antigenic activity in cell fractions. Data presented here indicate that passive hemagglutination provides as effective a means of visualizing antigenic activity as does immunofluorescence. Evidence showing that melanoma-specific antigenic activity is present as a soluble component in the cytosol and as a membrane-associated component of the endoplasmic reticulum is also presented.