Chimeric bone marrow cultures (one from each mouse) were set up from selected animals transplanted with either PBCs or CBCs and cultured for 2 to 3 weeks as described in “Patients, materials, and methods.” Confluent stromal layers were fixed and stained using monoclonal human-specific antibodies directed to the indicated antigens and subsequent immunoperoxidase staining. Cultures from bone marrow of nontransplanted mice were run in parallel and stained negative for all antihuman antibodies used. The percent values are means ± SD of the positive (engrafted) mice. The cultures were derived about equally from mice transplanted with either CD34⁺ PBCs or CBC-mononuclear cells. No differences were observed between results from the 2 blood sources.

Clones of monoclonal antibodies recognizing different epitopes expressed on human fibroblasts (see “Patients, materials, and methods”).