The biodistribution of the 202 monoclonal antibody against CEA labeled with 88 Y by the bicyclic DTPA anhydride method was studied in normal Balb/c mice. The in vitro binding to 1 × 10 7 CO112, LS174T and WiDR colon cancer cells was 21.0, 27.3 and 18.8%, respectively. The binding to an equal number of KM-3 leukemia cells and normal human lymphocytes was 8.9 and 3.2%, respectively. Liver, spleen, kidney and blood were the tissues that showed the highest uptake of radiolabeled antibody in vivo. © 1985.