We describe here the generation and characterization of a human monocl
onal IgG antibody (UL/F14) specific for HLA-B12. The antibody is suita
ble for complement-dependent lysis on lymphoblastoid cell lines and st
imulated peripheral blood mononuclear cells. UL/F14 competes for antig
en binding with an HLA-B12 human monoclonal IgM antibody and with a sp
ecific alloantiserum. Protein chemistry shows that the monoclonal anti
body UL/F14 can precipitate solubilized HLA-B12 molecules.