Donor type chimerism after transplantation of different BM cell fractions into allogeneic recipients exposed to sublethal (7 Gy) TBI: effect of positive selection for Sca-1⁺ cells and subsequent depletion of Lin⁺ cells. The figure shows peripheral blood chimerism at 30 days after transplantation of 1 × 10⁶ cells from each cell fraction.