Figure 3: YTZ3-15 effectively delivers siRNA to SUM 1315 cells. (a) Left: nontransfected SUM 1315 cells had low background fluorescence. Right: more than 99% of YTZ3-15 transfected cells were positive for AlexaFluor 647-labeled siQ. (b) Fluorescent microscopy revealed that AlexaFluor 488-labeled siQ was taken up into cells within one day, and AlexaFluor signal was still detectable in cells at seven days after transfection. (c) Confocal images of SUM 1315 cells stably expressing eGFP + luc and transiently transfected with AlexaFluor 647-labeled siQ using YTZ3-15. LysoTracker dye revealed that siQ primarily colocalized with mid to late endosomes after 24-hour incubation with YTZ3-15 siRNA dendriplexes.