Brief Communication: Separation of Two Distinct Tumor-Associated Anti- bodies in the Serum of Melanoma Patients 1

SUMMARY-Two antibody/antigen reactions, previously described in human malignant melanoma, were studied by cross-absorption, immunofluorescence, and immunodiffusion techniques. Two different melanoma cell suspensions and their autologous positive sera were used to separate antibodies in the sera so that the common antibody against cytoplasmic contents was absorbed out, thus leaving a patient-specific antibody directed against the individual cell surface membrane. This further con Arms the relative specificity of the antibody/antigen reaction in human malignant melanoma and offers a method for study of the relationship between these 2 antibodies and circulating antigen in the natural history of this tumor.-J Natl Cancer Inst 49: 915-917, 1972. TUMOR-SPECIFIC ANTIBODIES against hu-man malignant melanoma cells have been detected by immunofluorescence (1-4). Using immuno-fluorescence, we recently reported the appearance of two types of reaction on individual malignant melanoma cells: one directed against the cyto-plasmic contents of snap-frozen cells and the othe