THE DEVELOPMENT OF MONOCLONAL-ANTIBODIES AGAINST THE CYTOKININ ZEATIN RIBOSIDE

Seven monoclonal anti-zeatin riboside antibodies were characterized by radioimmunoassay (RIA) and found to measure femtomole (10-15 M) quantities (∼20 pg) of this cytokinin. The antibodies had different measuring ranges defined by the linear portion of the logit/log plots; slopes and intercepts of the line varied considerably between the antibodies. Competitive binding trials against cis-zeatin riboside (cZR), dihydrozeatin riboside (diHZR), zeatin (Z), and isopentenyl adenosine (iPA) showed differences among the seven antibodies in their cross-reactivities towards these structurally related cytokinins. It was possible to combine selected antibodies to provide a mixture with a predictable measuring range and cross-reactivity; the ability to prepare a highly specific reagent in this manner with well-defined reactivity was noted and differences between monoclonal antibody and polyclonal antiserum probes for measurement of cytokinins were discussed. © 1991 Springer-Verlag New York Inc.