Fig. 4

Labeling of CCE-HPCs with Gd₂O₃-TRITC-MSN: GFP^dim and GFP^hi HPCs show differential levels of nanoparticle uptake. c Composite GFP and TRITC fluorescent micrograph showing CCE-HPCs (green) labeled with MSNs containing TRITC (red). a, b, d-f Cytometry data for these cells, with 87% of cells showing positive signal for both TRITC and GFP (b). Cell population seems separated into two distinct subpopulations, explored in bottom row (d-f). Subpopulation marked by green oval (GFP^dim, FSC^lo) shown in middle panel is 98.3% TRITC⁺ with three distinct peaks of nanoparticle uptake. Subpopulation marked by red oval (GFP^hi, FSC^hi) is 73.6% TRITC⁺. Two subpopulations are nearly equal in size (n = 2). FSC forward scatter, GFP green fluorescent protein, SSC side scatter