Analysis of bone marrow cells.

(A) Comparative flow cytometric analysis of embryonic and adult bone marrow cells. Embryonic E13.5 and adult BM cells were stained with the RR5 and c-kit mAbs and analyzed by flow cytometry in the FSC/SSC progenitor window. The RR5/c-kitdouble-positive cells shown in the window were sorted for intrathymic injection and in vitro differentiation. (B) Analysis of myeloid and erythroid potential of sorted cells from E13.5 BM. The 1000 cells from each sorted population were cultured in duplicate in erythroid differentiation medium. Results represent the mean number of colonies scored in duplicate cultures from one representative experiment (of 5 experiments). M: macrophage; G: granulocyte; M/G: macrophage/granulocyte; Eb/Ec: erythroblast/erythrocyte colonies. No colonies were obtained from the double negative population. ■ indicates M,G, and M/G; ▨ indicates Eb/Ec. (C) Rhodamine staining of RR5/c-kit double-positive BM cells. Comparative Rh staining of total bone marrow cells (hatched line) and RR5⁺/c-kit⁺ cells (continuous line). (D) Cyclin A and B staining of RR5/c-kit double-positive BM cells. Cyclin staining of embryonic total bone marrow cells (thin line) and RR5⁺/c-kit⁺ cells (bold line). Control: normal rabbit serum; cyclin A: polyclonal rabbit antichicken cyclin A serum; cyclin B: polyclonal rabbit antichicken cyclin B serum. Rabbit antibodies were detected by a goat antirabbit antibody conjugated to FITC.