Localization of adoptively transferred monocytes in lymph node and spleen differs with antibody treatment. Freshly isolated EGFP bone marrow–derived monocytes (8 × 10⁶) were injected intravenously into control mice or mice immunized 21 to 24 days previously with peptide to induce EAU. Mice were then treated with mAb for up to 3 days. Groups of mice were killed at 30 minutes and 24 hours after a single treatment or after 3 treatments. Tissue samples were then snap frozen, cryosectioned, and immunostained using the APPAP technique (A-D) for the presence of EGFP⁺ cells using a specific antibody, or examined by confocal microscopy (E,F). Original magnification ×400 (A-D); ×200 (E); ×640 (F).