VEGFR distribution in MS1 and MS1-VEGF cells and the affinity of angiogenesis factor-conjugated QDs to these cell lines. (A-D) Immunostaining of MS1 and MS1-VEGF cells with an anti-VEGFR antibody. Scale bar represents 50 μm. (E-H) Typical images of cells treated with fluorescent particles. MS1 and MS1-VEGF cells were treated with unconjugated QDs, PDGF-QDs, or VEGF-QDs. Representative images are shown of cells treated with PDGF-QDs and VEGF-QDs. Data from cells treated with unconjugated QDs are not shown. White dots represent fluorescent QDs; and white dotted lines, the outline of the cell. Scale bar represents 10 μm. (I) QD fluorescence intensity per cell. The fluorescence intensity of QD signals from the cells was analyzed as gray values. In each condition, n = 30. **P < .01. Error bars represent SEM.