Monoclonal antibodies (MAbs) have been prepared with specificity for diethylenetriaminopentaacetic acid (DTPA) used to chelate metal radioisotopes to immunoglobulins for radioimmunoimaging and radioimmunotherapy. The use of fusion partners of lymph node-derived B cells resulted more frequently in the isolation of IgG secreting hybridomas than with splenocytes. All MAbs have been selected for simultaneous recognition of chelated and unchelated DTPA, and have been characterized in their biochemical, physico-chemical and immunochemical features. In view of the potential use in development of bifunctional MAb, these novel MAbs were also proven to lack detectable cross-reactivity with normal human tissues.