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Updated: Jun 25, 2026
09:19
Spectroscopic Super-resolution Imaging of DNA Molecules using Intrinsic Contrast
Published on: March 6, 2026
A turn-on fluorescent nucleoside enabling sequence-insensitive DNA labeling
Jinsi Li1,2, Ziwen Dai1, Lei He1
1Shenzhen Key Laboratory of Synthetic Genomics, Guangdong Provincial Key Laboratory of Synthetic Genomics, State Key Laboratory of Quantitative Synthetic Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China.
Nucleic Acids Research
|June 24, 2026
Summary
Researchers developed a new fluorescent nucleoside, thiazolyl-dU (TzdU), that significantly enhances DNA imaging. This novel tool offers bright, stable fluorescence in DNA, overcoming limitations of previous fluorescent nucleobase analogs.
Area of Science:
- Molecular Biology
- Biochemistry
- Biophysics
Background:
- Fluorescent nucleobase analogs (FBAs) are crucial for studying nucleic acid structure and dynamics.
- Existing FBAs suffer from fluorescence quenching and sequence-dependent brightness variations.
- These limitations hinder reliable DNA fluorescence imaging and analysis.
Purpose of the Study:
- To develop a novel "turn-on" nucleoside analog for enhanced DNA fluorescence imaging.
- To engineer a fluorescent nucleobase analog that overcomes quenching and sequence-sensitivity issues.
- To create a reliable tool for real-time monitoring of DNA-related enzymatic processes.
Main Methods:
- Synthesis of a novel thiazolyl-dU analog (TzdU).
- Characterization of TzdU fluorescence in single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA).
- Assessment of TzdU stability against common quenching mechanisms (collisional quenching, ESPT).
- Evaluation of TzdU triphosphate utilization by DNA polymerases (Deep Vent, KOD XL) for PCR and primer extension.
- Demonstration of gradient illumination for DNA visualization and information encryption.
Main Results:
- TzdU exhibits a 10-fold increase in brightness in ssDNA and up to 50-fold in dsDNA compared to its free form.
- TzdU maintains stable fluorescence intensity irrespective of neighboring bases, evading quenching pathways.
- The triphosphate form of TzdU is efficiently incorporated by DNA polymerases.
- TzdU enables label-free, real-time monitoring of PCR and primer extension.
- TzdU facilitates gradient illumination for DNA visualization and information encryption.
Conclusions:
- TzdU is the first FBA with universal turn-on characteristics, sequence insensitivity, and enzymatic compatibility.
- TzdU represents a significant advancement for investigating nucleic acid dynamics.
- This novel analog opens new avenues for fluorescence-based DNA imaging and methodologies.
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