Phenotype and differentiation potential of mesenchymal stem cells (MSCs). Bone marrow cells of DBA/1 wild-type and interferon-gamma receptor knockout (IFN-γR KO) mice were cultured in Murine Mesencult medium and phenotyped. (a-d) MSCs were incubated with the indicated antibodies and analyzed by flow cytometry. Grey histograms show stained cells, and black lines represent cells incubated with isotype controls. Wild-type MSCs were analyzed at passages 3, 4, and 7 (a) and IFN-γR KO MSCs were analyzed at passages 2 and 12 (b) for expression of CD11b, CD45, and Sca-1. Likewise, other phenotypic markers were analyzed on wild-type (c) and IFN-γR KO (d) MSCs. (e) MSCs were cultured to confluency in Murine Mesencult medium and then transferred to adipogenic or osteogenic differentiation medium for 21 days, followed by Oil Red O or Alizarin Red staining, respectively (original magnification × 10). The inset in the lower right panel represents an enlargement of the adipocyte indicated by the arrow.