Figure 3.

FDC clusters are absent from both spleen and LNs of TNFR-I^−/− and LT-α^−/− mice. Sections of spleen and LNs were prepared as in Fig. 1 and stained with biotinylated-8C12 (PharMingen) to detect FDCs (blue) and anti-B220 (brown). a–f are as in Fig. 1. (a–d and f, ×100; e, ×40.)