Dimeric cyanine dye as effective probe for quadruplex DNA

UV-visible spectroscopy of the dimeric dye reveals specific property of dye to remain as aggregated form in biological solutions which unfolds in presence of specific G rich DNA structure. This ability of dye has been proven by UV-vis and Fluorescence experiments. Dye is used a marker for the presence of quadruplex and its conversion to duplex on addition of complementary sequence. Fluorescence intensity varies tremendously in both the cases. Quadruplex being a highly stable structure gives a very high fluorescence which gets quenched on duplex formation. Study of the dye binding behavior with quadruplex DNA reveals more than one kind of binding complexes that exist between DNA and monomeric species of dye.