Thioflavin T as an Efficient Inducer and Selective Fluorescent Sensor for the Human Telomeric G-Quadruplex DNA

The quest for a G-quadruplex specific fluorescent sensor among other DNA forms under physiological salt conditions has been addressed in this article. We demonstrate for the first time the application of a water-soluble fluorogenic dye, Thioflavin T (ThT), in a dual role of exclusively inducing quadruplex folding in the 22AG human telomeric DNA, both in the presence and absence of Tris buffer/salt, and sensing the same through its fluorescence light-up having emission enhancement of the order of 2100-fold in the visible region. Appropriate conditions allow an apparent switch over of the parallel quadruplex structure in 22AG-ThT (50 mM Tris, pH 7.2) solution to the antiparallel form just by the addition of K(+)…

• II
  Indian Institute of Technology Bombay
• BO
  Board of Research in Nuclear Sciences