Gadolinium labeled antibodies as specific contrast agents in MRI

Paramagnetic substances can be used as agents for altering contrast in NMR images. In order to enhance specificity with respect to a particular organ or pahtology, a paramagnetic ion may be coupled to a specific carrier such as a monoclonal antibody (MoAb). In this investigation a murine MoAb to a human melanoma associated antigen (225.28S from SORIN Italy) was employed. It was studied how it can be conveniently labeled and under what conditions the labeled complex can induce appreciabel variations of proton relaxation times at different frequencies. The relation of the efficiency of this effect to the structural and dynamical properties of the MoAb free in solution or boundin antigen is analyzed. (H.W.). 7 refs.; 1 fig.; 1 tab