Tumor-specific antigen for human renal cell carcinoma. Ultrastructural localization of the antigen by immunoelectron...

Hybridoma technology enabled the production of tumor-specific monoclonal antibodies reactive exclusively with human renal cell carcinoma. Intracellular localization of the antigen was undertaken in order to gain understanding of its possible physiological role in cellular metabolism and to investigate its future clinical applicability for immunoscintigraphy in tumor localization. For immunoelectron microscopy a special paraformaldehyde-periodate fixation process (PLP fixation) had to be employed, in order to preserve the cell's ultrastructure without destruction of the antibody-binding epitope. The antigen was found to be strictly intracytoplasmic in close correlation to the glycogen particles characteristic for human renal cell carcinoma. These findings suggest that this antigen may be involved in the pathological glycogen synthesis, explaining the specific staining pattern of these monoclonal antibodies.