Microscopic appearance of APCs in sections of tumors and after isolation as APCs-MB.

(A) Immunohistochemical staining of APCs with CD11b mAb (red) and mouse IgG plus antimouse IgG (green) in sections of small subcutaneous MOPC315 tumors (0.2-0.5 g) in TCR-transgenic mice. Cell nuclei are in blue. (B-D) Examples of stained APCs-MB, purified, attached to slides, and fixed within 2 hours after dissection of MOPC315 tumors. Anti-CD11b in red, MBs conjugated with mouse IgG2a-FITC in green, nuclei in blue. The arrow indicates a bead that has not been internalized. Beads are 4.5 μm in diameter.