Detection of different classes of clonogenic human progenitors contained in the marrow of chimeric transplantation recipients.

From the BM of mice receiving G₀CD34⁺, G₁CD34⁺, and S/G₂+MCD34⁺ FL or FBM cells, 2 × 10³ CD45⁺CD34⁺ cells were assayed in methylcellulose, as described in “Materials and methods.” The number of mice analyzed per group was different for different groups of cells as follows: FL, n = 12 for G₀; n = 10 for G₁; n = 6 for S/G₂+M; FBM, n = 8 for G₀; n = 4 for G₁; n = 2 for S/G₂+M. Data are presented as mean numbers ± SEM of clonogenic human progenitors contained in the marrow of chimeric transplantation recipients. The mean total number of colonies (clear bars) represent the arithmetic sum of derived colonies for erythroid burst-forming units (BFU-E, hatched bars), granulocyte/macrophage–colony-forming units (CFU-GM, striped bars); and granulocyte/erythroid/macrophage/megakaryocyte colony-forming units (CFU-GEMM, black bars).