Antibodies and antibody-based assays for hexavalent uranium

Three hybridoma cell lines (8A11, 12F6 and 10A3) have been generated that s ynthesize and secrete monoclonal antibodies that bind tightly and specifica lly to UO22+ complexed to 1,10-phenanthroline-2,9-dicarboxylic acid (DCP). These antibodies showed differences in their ionic strength and pH dependen cies. The three antibodies have been used to construct competitive immunoas says for soluble UO22+. In a competitive microwell immunoassay fonnat, the antibodies measured soluble UO22+ at concentrations ranging from 0.3 to 10 muM (9.5-2400 ppb). Metal ion specificity of the 8A11 antibody was determin ed by the individual addition of 1 ppm of 19 different atomic absorption-gr ade metals (Cu(II), AI(III), Mo(VI), Hg(II), Cd(II), Zn(II), Ni(II), Co(II) , Pb(II), Mn(II), Sr(II), Ca(II), Au(III), In(III), Fe(M), Ti(III), Yt(HI), Pr(III), or Er(III)) to the competitive microwell assay. The addition of t hese metals had no effect on the response of the immunoassay to soluble UO2 2+. In a competitive assay format that utilized the KinExA automated immuno assay instrument, the 8A11 antibody-based assay was linear with UO22+ conce ntrations from 1 to 5 nM (0.24-1.2 ppb). (C) 2001 Elsevier Science B.V. All rights reserved.