Tissue typing of cells in culture. III. HLA antigens of established human cell lines. Attempts at typing by the mixed hemadsorption technique.

Thirty established cell lines from solid human tumors were typed by the mixed hemadsorption technique with respect to the HLA-A and HLA-B and partly also the HLA-C series. All cultures exhibited unique antigenic patterns. The discriminatory potential was further increased very much taking into consideration one as yet undefined antigen series tentatively named Ek-1 to Ek-11. Sixteen cell lines not designated as HeLa cells but on various non-immunological indications suspected to be HeLa cell contaminants, all gave, with our present test, the same antigenic composition as HeLa cells or clones thereof. The mixed hemadsorption reaction is a highly sensitive and convenient method for immunological typing of cells in monolayer cultures. Some important implications of this are discussed.