| abstract |
Disclosed is a method for in vivo imaging tissue of a individual, by performing magnetic resonance imaging utilizing an extended cobalt complex as a contrast enhancement agent. The extended cobalt complex is comprised of cobalt atoms, a carboxylate ligand, an amine ligand, and a multidentate thiol-containing organic ligand, the cobalt atoms being linked to thiol groups and counter ions. The extended cobalt complex is characterized as stable, water soluble, non-aggregating, magnetic, and from 0.5 to 10 nm in size. This method is especially useful in imaging tumor tissue, and also tissue which is regenerating from a wound. The extended cobalt complex can be specifically targeted to a particular tissue to enable selective imaging of that tissue. This is done by linking the extended cobalt complex to a binding moiety which specifically binds a molecule selectively expressed in the tissue. Also disclosed is a method for visually detecting the presence of an antigen in a sample using an antibody which specifically binds the antigen, the antibody being coupled to an extended cobalt complex. In the method, the antibody is contacted to the sample under conditions appropriate for antibody-antigen binding, and the presence of the extended cobalt complex which is bound to the antigen is detected by its characteristic color or its magnetic properties. |