Fig. 11. Detection of Sca-1-like protein in human bone marrow. Shown is normal human bone marrow obtained from biopsy of the iliac crest. Sca-1-like positive cells were identified by immunocytochemistry and confocal microscopy. (A) Two cells positive for Sca-1-reactive protein (yellow fluorescence, arrows). The endothelial cell cytoplasm in this sample is detected by von Willebrand factor antibody labeling (red fluorescence). (B) Two cells expressing Sca-1-reactive protein (yellow fluorescence, arrows). (C) The two cells in B also express c-kit (green fluorescence, arrows). Blue fluorescence reflects propidium iodide staining of nuclei. (Scale bars = 10 m m.)