Abstract: Monoclonal antibodies produced after immunization with a synthetic antigen bearing the structure Gal (beta 1-3) GalNac beta-glycosidically linked to a carrier moiety are useful as carcinoma markers. Radioimmunoimaging agents are described in which such antibodies are tagged with radiometals or radiohalogens. Radiolabeled monoclonal antibody 155H.7, elicited by this antigen, rapidly localizes and persists in tumor tissues, demonstrating its utility as a tumor imaging agent.

Abstract: Use of labeled monoclonal antibody 50 H.19 to detect the location and concentration of blood platelets in a host is disclosed. MAb 50 H.19 labeled with a label which can be detected from without the host (e.g. a radiolabel or NMR-label) is intravenously injected to immunoreact with platelets in vivo or is first immunoreacted in vitro with platelets, which are then intravenously injected into the host. By means of the labeled MAb 50 H.19 bound platelets it is possible to detect and locate thrombi, emboli, atherosclerotic obstructions, bacterial endocarditis and to do spleen imaging. In another embodiment of the invention, the MAb 50 H.19 is bound to an enzymatic thrombolytic agent and injected intravenously to permit the therapeutic application of the agent directly to thrombi.