Biodistributions of radioactivity in blood, marrow, spleen, and normal organs of leukemic SJL/J mice injected with 125I-anti-mCD45 Ab. Leukemic mice were injected via the tail vein with 0.67 nmol of conventional trace-labeled 125I-anti-mCD45 Ab at time = 0 hours and killed 2, 4, 8, 24, 48, or 72 hours later. The radioactivity in blood, marrow, and spleen was quantified by gamma counting, corrected for decay and expressed as percent ID/g of tissue. Error bars are SD.