TODi-1 (Thiazole Orange Homodimer, also known as TOTO®-1) is a green fluorescent carbocyanine dimeric dye. TODi-1 is a cell-impermeant nucleic acid stain that is nonfluorescent in the absence of nucleic acids but exhibits a multiple fluorescence enhancement upon binding to dsDNA.
The bright fluorescence signal and low background make TODi-1 ideal for staining nucleic acids on microarrays, as well as for nuclear and chromosome counterstaining in multicolor fluorescence labeling experiments. TODi-1 is non-cytotoxic and may be used for long-term monitoring of cell viability and dead cell detection in culture.
