Figure 4.

Single cell measurements of MB and QD fluorescence. (a) QD–MBs in the absence of target or pre-hybridized to target we microinjected into MCF-7 cells. QD–MBs in the absence of target exhibited a bright fluorescent signal in the QD image but no signal was visible in the MB image. QD–MBs prehybridized to target exhibited a bright fluorescent signal in both the QD and MB images. In all images, the QD–MBs were only observed in the cytoplasmic compartment. (b) Single-cell measurements of total integrated MB fluorescence divided by total integrated QD fluorescence, following microinjection of QD–MBs in the absence of target (n = 19) and QD–MBs prehybridized to target (n = 13).