[Presence of 2 different epitopes on the human beta 2-microglobulin defined by monoclonal antibodies].

Two monoclonal antibodies recognizing monomorphic determinants on class I antigens of MHC were characterized. They were shown to recognize beta 2m by cytotoxicity inhibition studies. The epitopes recognized were different, as assayed by cross-inhibition and phylogenetical studies. One antibody recognized free as well as HLA-associated beta 2m. The other reacted with a conformational epitope which was well conserved during evolution.