Indirect rosette microassay to characterize human melanoma-associated antigens recognized by operationally specific xenoantisera.

The indirect rosette assay which detects the interaction of antibodies with target cells by their ability to rosette with sheep red blood cells chemically coated with purified anti-immunoglobulin antibodies or with protein A from Staphylococcus aureus has been used to analyze xenoantisera to human melanoma-associated antigens. The test has been developed as a microassay and performed in microtiter plates, thus facilitating the screening of large numbers of samples. When modified as an inhibition assay, the assay has been successfully used (a) to compare the specificities of xenoantisera elicited with cultured melanoma cells, hybrids derived from the fusion of cultured human melanoma cells, and murine fibroblasts and melanoma-associated antigens purified by biochemical procedures and (b) to investigate the relationship of melanoma-associated antigens with beta 2-microglobulin and HLA antigens on the membrane of melanoma cells.