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In vitro selection of molecular beacons
Manjula Rajendran1, Andrew D Ellington
1Department of Chemistry and Biochemistry, Institute for Cell and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA.
Nucleic Acids Research
|September 23, 2003
Summary
Researchers developed a novel selection method for molecular beacons, enabling direct selection of DNA aptamers that signal ligand presence with increased fluorescence. This technique simplifies aptamer beacon engineering for biosensing applications.
Area of Science:
- Biochemistry
- Molecular Biology
- Biosensor Technology
Background:
- Molecular beacons are established nucleic acid biosensors.
- Adapting aptamers as beacons requires expertise in sequence and structure.
- A general method for direct aptamer beacon selection is needed.
Purpose of the Study:
- To develop a general method for direct selection of aptamer beacons.
- To establish a selection method for molecular beacons applicable to aptamers.
Main Methods:
- Immobilized random DNA sequences on an affinity column via a capture oligonucleotide.
- Selected DNA variants released by a target oligonucleotide were amplified.
- Incorporated fluorescent reporter and DABCYL quencher for signal detection.
Main Results:
- Nine rounds of selection and amplification significantly improved elution characteristics.
- Target oligonucleotide addition released the capture oligonucleotide, increasing fluorescence up to 17-fold.
- Signaling demonstrated specificity for the target oligonucleotide via a novel mechanism involving helical junction formation.
Conclusions:
- The developed selection method allows direct selection of molecular beacons.
- This approach simplifies aptamer beacon engineering, reducing reliance on prior sequence/structure knowledge.
- The method is adaptable for selecting beacons for diverse, including non-nucleic acid, targets.