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Updated: Jun 17, 2026

Single-Molecule Fluorescence Visualization of DNA Polymerase Dynamics at G-Quadruplexes
Published on: April 4, 2025
G4-FID: a fluorescent DNA probe displacement assay for rapid evaluation of quadruplex ligands
David Monchaud1, Marie-Paule Teulade-Fichou
1Institut Curie, Section Recherche, CNRS UMR 176, Center Universitaire Paris XI, Orsay, France.
Abstract:
Currently, small molecules able to interact specifically with G-quadruplex DNA (G-quadruplex ligands) are intensively studied since they appear to inhibit the growth of cancer cells via an unprecedented mode of action based on structural perturbation of telomeres. It is thus of crucial interest to develop methods that enable easy, rapid and reliable detection of valuable candidates. Herein, we would like to report on the G4-FID assay, a simple fluorescence screening method based on the displacement of a DNA light-up probe (thiazole orange) from both quadruplex and duplex DNA, therefore allowing a concomitant evaluation of the quadruplex-affinity and quadruplex- over duplex-selectivity of the tested candidates.
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