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Updated: Jan 27, 2026

Single-Molecule Fluorescence Visualization of DNA Polymerase Dynamics at G-Quadruplexes
Published on: April 4, 2025
Spiropyran in Situ Switching: A Real-Time Fluorescence Strategy for Tracking DNA G-Quadruplexes in Live Cells
Jin Li1, Xinchi Yin2, Bin Li1
1Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, National Demonstration Center for Experimental Chemistry Education, College of Chemistry and Materials Science, Key Laboratory of Resource Biology and Biotechnology in Western China of the Ministry of Education , Northwest University , Xi'an 710127 , P. R. China.
Abstract:
DNA G-quadruplexes (G4s) in vivo have been linked to cancer and other diseases such as neurological disorders. Nondestructive fast detection of endogenous DNA G4s can provide specific real-time information, which is of particular interest for clinic accurate diagnosis. However, tools to probe live-cell endogenous DNA G4s in real time are very limited. Herein, we report the design and development of a fluorescent molecule QIN for the real-time detection of endogenous DNA G4s in live cells with the aid of a new spiropyran in situ switching (SIS) strategy. The lipophilic spiropyran-linked QIN differs from the other probes in that it can enter live cells readily within 15 s and can be in situ induced by DNA G4s to adopt its charged open form, causing a large red shift in the fluorescent emission wavelength. Live-cell super-resolution fluorescent imaging suggests that the SIS-based probe has high photostability and can be applied for the accurate detection of DNA G4s in complex biosystems with very high sensitivity and selectivity.
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