NOD-SCID engraftment potential of CD133⁺ cells. Purified human BM CD133⁺ cells were engrafted into NOD-SCID mice by IV injection. After 6 weeks or when animals showed signs of adverse events, BM cells were isolated from NOD-SCID mice and analyzed for the presence of human cells. (A) Flow cytometric analysis for human CD45 expression. (B) Immunohistochemical staining of NOD-SCID BM for human-specific MHC-1 Abs. B indicates bone. Scale bar indicates 100 μm. (C-D) Flow cytometric analysis for human progenitor cell subsets (C) and human hematopoietic lineage engraftment (D).