CD34⁺ cells that have divided during 6 days of culture in TPO, KL, and FL retain their capacity for in vivo marrow repopulation in the SCID-hu bone assay. Uncultured CD34⁺Thy-1⁺Lin⁻ BM cells and CD34^hi PKH^lo and CD34^lo/−PKH^lo cells from D6 TPO, KL, and FL cultures were injected into SCID-hu bone grafts (10,000 cells per graft). FACS analysis at 8 weeks showed multilineage marrow repopulation by both the uncultured cells and the CD34^hi cells postdivision in culture (PKH^lo). The x-axis shows staining for donor HLA allotype. The y-axis shows staining for total human cells (W6/32, antihuman class I MHC) or lineage markers.