HEK293 cells were stained and observed at a high magnification (× 20) at 6 days post-transfection. HEK293 cells were cells cultured and stained with PI and Hoechst dye at 6 days after transfection. The seeding density was consistent in all experimental groups (4 × 104cells/well). A, HEK293 cells transfected with pCMV6-rVegfr2 plasmid (0.15 μg/well plus pCMV-gfp plasmid (0.10 μg/well); B, HEK293 cells transfected with pCMV6-truncated-rVegfr2 plasmid at 0.15 μg/well plus pCMV-gfp plasmid (0.10 μg/well; and C, control group (HEK293 cells transfected with pCMV-gfp plasmid (0.10 μg/well)). rVegfr2: rat-Vegf-receptor2. Scale bar: 200 um.