A simple and sensitive method to measure radiolabeled antibody uptake by tumors in nude mice.
A method for detecting the uptake of 125I-labeled monoclonal antibody by human tumors xenografted into nude mice is described. After implantation of the tumor intramuscularly in one of the forelimbs, radioactivity was measured in the area of tumor inoculation and in the contralateral normal forelimb. For these measurements, a lead apparatus was constructed which shielded over 99% of the whole body radioactivity and permitted efficient counting of 125I in the exposed portion of each forelimb. For each tumor an uptake ratio (UR) was calculated for the radioactivity in the tumor compared to muscle. With this shield apparatus, reproducible, sensitive and relatively rapid determinations of UR values can be obtained. Antibody localization can be detected in some tumors which are nonpalpable or very small and for tumors of up to 2 cm3 in volume. Whole-body radioactivity ranging from less than 0.037 MBq to higher levels suitable for radioimmunoscintigraphy could be utilized in this procedure.
Cancer Research Laboratory, St. Joseph Hospital, Houston, TX 77002.
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Lockshin
D000818:Animals; D000911:Antibodies, Monoclonal; D006801:Humans; D007457:Iodine Radioisotopes / Q000378:metabolism; D051379:Mice; D008819:Mice, Nude; D009374:Neoplasms, Experimental / Q000000981:diagnostic imaging* / Q000378:metabolism; D011835:Radiation Protection / Q000295:instrumentation; D011877:Radionuclide Imaging; D012588:Scintillation Counting / Q000379:methods; D013997:Time Factors; D014183:Transplantation, Heterologous
D000911:Antibodies, Monoclonal; D007457:Iodine Radioisotopes