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Updated: Jan 8, 2026
Fluorescent Labeling of COS-7 Expressing SNAP-tag Fusion Proteins for Live Cell Imaging
Published on: May 17, 2010
A bright and regenerative array tag with fluorogenic ligands for long-term live-cell nanoscopy and single-molecule
Dongjuan Si1, Zhihao Dong1, Gang Xing1
1School of Pharmaceutical Sciences, MOE Key Laboratory of Smart Drug Delivery, MOE Innovative Center for New Drug Development of Immune Inflammatory Diseases, Endoscopy Center and Endoscopy Research Institute, Zhongshan Hospital, Fudan University, Shanghai, 201203, China.
Researchers developed ReTagX, a novel fluorescent tag system for live-cell imaging. This regenerative system overcomes photobleaching, enabling long-term, high-resolution visualization of cellular dynamics.
Area of Science:
- Cellular Biology
- Biophysics
- Microscopy
Background:
- Live-cell nanoscopy and single-molecule tracking are vital for cellular biology.
- Current fluorescent tags suffer from low brightness, large size, and photobleaching, limiting applications.
Purpose of the Study:
- To introduce ReTagX, a bright, regenerative, compact array tag system.
- To enable rapid recovery of photobleached signals via reversible, fluorogenic labeling for improved live-cell imaging.
Main Methods:
- Development of ReTag1 (~18 kDa) with MaP655-TMP for high fluorogenicity.
- Utilized ReTagX for Stimulated Emission Depletion (STED) imaging of mitochondrial TOM20.
- Applied ReTagX arrays (e.g., ReTag8, ~156 kDa) for single-molecule tracking of TNFR2.
Main Results:
- ReTag1 achieved up to 204-fold signal-to-noise ratio with fluorescence recovery in 1 minute.
- Extended STED imaging of mitochondrial dynamics to over 100 minutes at 80 nm resolution.
- Multimeric ReTag1 arrays increased brightness 5.5-fold and extended TNFR2 tracking by ~2.9-fold.
Conclusions:
- ReTagX offers a robust platform for high-resolution, long-term molecular visualization in live cells.
- The system overcomes limitations of traditional fluorescent tags, enhancing cellular dynamics studies.
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