Analysis of Lin⁻ marrow cells from primary recipients transplanted with CD34⁺ cells. (A) Dotted and solid lines represent cells stained with isotype-matched Ig and Ly-5.1–specific antibody. Sixty-five percent of the Lin⁻marrow cells of the primary recipients were donor-derived (Ly-5.1) cells. (B) Sorting windows of Ly-5.1⁺ Lin⁻c-kit⁺ Sca-1⁺ cells. The ratio of the cells in R9 to R10 was 1:5.