Comparison of long-term repopulating activity in Thy-1.1^lowSca-1⁺Lin⁻ HSC separated using Rh-123 (A) or BodVer (B). The brightest and dullest 15% of cells in each staining distribution were isolated from Ly-5.1 bone marrow, and the indicated numbers of each population were transplanted into lethally irradiated Ly-5.2 recipient animals in the presence of 10⁵ normal Ly-5.2 bone marrow cells. Each animal (represented by each set of bars in the graphs) was bled 4, 6, 8, and 12 weeks posttransplant (time points are represented by individual bars within each set of four bars in the graphs), and Ly-5.1 peripheral blood cells were identified and phenotyped by flow cytometry.