Tonsillectomy remains a frequently performed operation in developed countries ensuring that tonsils are the most readily available source of human lymphoid tissue and an easily accessible source of dendritic cells (DC). Tonsil lymphoid tissue also provides a source of the different DC that are resident within the B- and T-cell microenvironments. Although an alternative model for follicular dendritic cell (FDC) ontogeny has been proposed (1) the FDC within tonsil B cell areas probably develop in situ from mesenchymal precursors (2). Whatever their origin, the phenotype and function of FDC (3) seem to be unrelated to the bone-marrow-derived DC that are the subject of these protocols. The precise relationship between the distinct sub-populations of the bone-marrow-derived DC within the tonsil is still not clear (see ref. 4 for review).