Detection of B-cell reconstitution in μMT → B6 chimeras. (A) Staining of spleen cells from μMT → B6 chimeras with anti-immunoglobulin antibodies 3 months after preparation. A representative staining profile of a B6 → B6 chimera as well as the staining profile of a donor μMT mouse are shown. All samples were stained with polyclonal rat antimouse immunoglobulin antibodies that were labeled with FITC. (B) μMT → F1 chimeras and control B6 → F1 chimeras were prepared as described in “Materials and methods.” Reconstitution of blood lineages was assessed by antibody staining of lymph node and spleen cells with anti-Thy-1 antibodies (biot-J1j) for T-cell lineage identification, PE–anti-CD19 for B-cell lineage identification together with anti–class I antibodies specific for H-2D^d molecules (FITC-34-4-21S). (C) Myeloid lineages were analyzed by staining peritoneal cavity cells with anti–H-2K^b (right panels) or anti–H-2K^d (left panels) antibodies. Representative staining profiles for one mouse from each group (μMT → F1 and B6 → F1, broken lines) are shown. Staining of normal F1 mice with each antibody is depicted by solid lines.