The cationic structure of Nuc-DAOTA + ensures strong electrostatic interactions with the negatively charged nucleic acids, especially DNA, that work as the driving force for targeting the live-cell nucleus. The longer excitation/emission wavelengths and high photochemical stability, in contrast to most of the commercially available nucleus staining probes, makes it particularly appealing for monitoring the different phases of cell division, including mitosis and interphase in live cells. In addition, the long-fluorescence lifetime of Nuc-DAOTA + was investigated for its applicability in FLIM and time-gated imaging of fixed 3T3 cells by comparing with the commercial dye, MitoTracker Red CM-H2XRos.