Tumor-to–normal organ ratios of absorbed radioactivity using each Ab/SA conjugate individually or all 3 in combination. Mice were treated as described in Figure 3. Tumor-to–normal organ ratios of radioactivity are shown 48 hours after injection of ¹¹¹In-DOTA-biotin. Animals were pretargeted with 1.4 nmol of either 1F5/SA (□), Lym-1/SA (▩), or HD39/SA (■) or a combination of either 0.47 nmol (▤) or 1.4 nmol of each conjugate (▧). Results are shown for mice bearing Ramos (A), Raji (B), and FL-18 (C) xenografts.