Precise and Stable Labeling of Quantum Dots with Engineered Antibodies
Victor R Mann1, Cassio C S Pedroso1, Bruce E Cohen2,3
1The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
Methods in Molecular Biology (Clifton, N.J.)
|August 7, 2026
Summary
We developed a new method using SpyCatcher and SpyTag proteins to stably attach antibodies to quantum dots (QDs). This technique allows for precise control over antibody attachment for improved live cell imaging.
Area of Science:
- Bioconjugation chemistry
- Nanotechnology for bioimaging
- Cellular and molecular imaging
Background:
- Quantum dots (QDs) are valuable for quantitative bioimaging but need specific surface functionalization for targeting cellular components.
- Current methods for conjugating antibodies (Ab) to QDs often lack control over stoichiometry and antibody orientation, potentially affecting imaging performance.
Purpose of the Study:
- To develop a robust and controlled method for conjugating antibodies to quantum dots for enhanced bioimaging applications.
- To enable precise stoichiometry and orientation of antibodies on QD surfaces.
Main Methods:
- Utilized the SpyCatcher-SpyTag protein ligation system for stable, covalent antibody-QD conjugation.
- Developed protocols for immunolabeling of CdSe/CdS QDs with miniaturized antibodies.
- Characterized the QD-antibody conjugates and validated their performance in live cell imaging.
Main Results:
- Successfully created stable QD-antibody conjugates with controlled stoichiometry and orientation.
- Demonstrated the utility of these conjugates for specific live cell imaging.
- The SpyCatcher-SpyTag system provided a reliable and efficient conjugation strategy.
Conclusions:
- The SpyCatcher-SpyTag protein ligation system offers a superior method for QD-antibody conjugation compared to existing techniques.
- This approach enhances the utility of QDs as probes for quantitative and targeted live cell bioimaging.
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