Stem cell toxicity in mice treated with TMTX plus NBMPR-P. Hemoglobin electrophoresis patterns of donor mice (panels A and B) and recipient mice after transplant (panels C through H) are shown. Genetically anemic W/W^v mice were transplanted with mixtures of BM cells from C57Bl/6J mice, homozygous for the single hemoglobin allele (panel A), and from HW80 mice, homozygous for the diffuse hemoglobin allele (panel B). The different hemoglobin patterns seen in recipients 10 weeks after transplant reflect the relative stem cell content from each of the donor grafts (panels C through H). Marrows from untreated C57Bl/6J and HW80 donors were mixed in a 50%:50% or a 30%:70% volume:volume ratio and a total of 2 × 10⁷ nucleated cells were injected in recipient mice (panels C and D). C57Bl/6J donors were also treated with the various drug regimens indicated in panels E through H and described in Results. These mixtures were injected into recipients and the reconstitution patterns seen 10 weeks after transplantation are shown in panels E through H.