Biodistributions of ¹¹¹In-DOTA-biotin in tumor xenografts and normal organs after pretargeting with each Ab/SA conjugate. Athymic BALB/c mice bearing Ramos, Raji, or FL-18 tumor xenografts were injected intravenously with 1.4 nmol of a single conjugate. After 24 hours, mice were injected with 5.8 nmol CA followed 3 hours later with 1.2 nmol ¹¹¹In-labeled DOTA-biotin. Mice were killed 24 and 48 hours later and blood, tumors, and normal organs were harvested, weighed, and analyzed for levels of radioactivity by γ-counting to determine %ID/g. Results are shown for PRIT with 1F5/SA (A), Lym-1 (B), HD39/SA (C), and the nonbinding control conjugate HB8181/SA (D). For each organ, the first bar represents results 24 hours after ¹¹¹In-DOTA-biotin injection and the second bar represents results after 48 hours.