Long-term multilineage reconstitution by a single SP. Single SP^low cells as shown in Figure 3, also selected for Sca-1 expression, were sorted into wells of a 96-well plate and transplanted into lethally irradiated recipients. (A) Carrier cells for the different transplantation experiments were as follows: (1) 2 × 10⁵ WBM; (2) 1-3 × 10⁵ Sca-1⁺ c-Kit⁺ depleted; and (3) 600 or 1000 Lin^–Sca-1⁺ c-Kit⁺ CD34⁺. Donor chimerism was determined as the percentage of CD45.2⁺ cells of the total number of CD45⁺ peripheral blood cells. Dots represent engrafted mice at 6 months after single-cell transfer. (B) Representative long-term follow up of 4 single HSC transplant recipients. Chimerism in peripheral blood was assessed by CD45.2 staining. Each line represents an individual mouse. (C) Lineage analysis in 1 representative chimera with 85% PB contribution 4 months after one HSC transplantation demonstrates contribution to the myeloid (top), T-cell (middle), and B-cell (bottom) lineages. Numbers represent the percentage of cells in each quadrant.