A and B: Immune Histochemistry (IHC) for CD146 expression of normal human bone marrow ( Panel A is an isotype antibody control. CD146 positive cells are present in a perivascular distribution, a location consistent with other models of where the HSPC niche might reside.
C: Flow-cytometry analysis of MSC cultures after 1 passage ( 10–14 days of culture). A variable proportion of cells are CD146 positive and they inhabit of continuum of antigen expression. Two MSCs set up from separate donors are shown.
D: Typical flow-sorting results from CD146-based sorting of MSCs. Approximately 35% of cells are deemed CD146 positive ( pre-sort, top histogram), and sorted to negative ( middle histogram) and CD146 negative ( bottom histogram) using a FACS-ARIA sorter ( Beckton Dickinson and Company) with a 100 μM nozzle.