Figure 4

Labeled donor cells in recipient lung. A representative image of a QD-labeled donor cell (arrow) as detected in recipient's lung tissue under confocal microscopy (A). Blue denotes nuclei stained with Hoechst 33342, green is autofluorescence from lung tissue, and red is emission signal from quantum dots. The graph (B) shows the wavelength and fluorescence level of QDs on the labeled cell (circle) and lung tissue (square). The sharp peak at 655 nm indicates that the emission from QDs is very distinct from the autofluorescence of lung tissue. Scale bar is 10 μm.