Figure 3.

Sensitivity of flow cytometric detection of human fetal bone marrow cells mixed with mouse bone marrow. Human cells were analyzed alone or mixed with NSG-BM cells over a range of 0.006% to 100% calculated based on the dilution of human cells (A). Human cells were defined as CD59-AF700⁺ events that were negative for staining with PI and the murine mAbs TER-119-PB, CD45-PB, and H-2K^d-PB. Note that the data are presented on a logarithmic scale. A subset of these data for dilutions containing <1% human cells is shown in (B). Only in samples containing a calculated 0.81% human cells or higher was there a significant (P≤0.05, asterisk) presence of human cells detected compared to samples of pure murine BM. A gray box indicates 1 SE above and below the mean of the pure murine BM measurements (n=3). The same samples shown in (B) were also stained with CD45-PE and B2M-FITC, for which the percentages of positive events are shown in (C) and (D), respectively. Detection of human CD59⁺ cells in BM harvested from an NSG mouse transplanted with human FBM diluted with varying amounts of untransplanted NSG-BM is shown in (E). Data are shown as the mean±SE, n=3-4 samples.