Molecular Beacon Assay
Molecular Beacon Assay - Related Videos
15:01
Quantitative, Real-time Analysis of Base Excision Repair Activity in Cell Lysates Utilizing Lesion-specific Molecular Beacons
0 Views •
Cited by 31 •
2012
We describe a method for the quantitative, real-time measurement of DNA glycosylase and AP endonuclease activities in cell nuclear lysates. The assay yields rates of DNA Repair activity amenable to kinetic analysis and is adaptable for quantification of DNA Repair activity in tissue and tumor lysates or with purified proteins.
03:49
A Molecular-Based Assay for Quantifying Influenza A and B Viruses
0 Views •
2025
The video demonstrates an assay for quantifying influenza viruses A and B. This assay employs nicking endonuclease amplification with influenza-specific primers and target detection using molecular beacon probes.
12:20
Real-time Imaging of Single Engineered RNA Transcripts in Living Cells Using Ratiometric Bimolecular Beacons
0 Views •
Cited by 1 •
2014
Ratiometric bimolecular beacons (RBMBs) can be used to image single engineered RNA transcripts in living cells. Here, we describe the preparation and purification of RBMBs, delivery of RBMBs into cells by microporation and fluorescent imaging of single RNA transcripts in real-time.
12:02
Molecular Evolution of the Tre Recombinase
0 Views •
Cited by 4 •
2008
Here we report the generation of Tre recombinase through directed, molecular evolution. Tre recombinase recognizes a pre-defined target sequence within the LTR sequences of the HIV-1 provirus, resulting in the excision and eradication of the provirus from infected human cells. While still in its infancy, directed molecular evolution will allow the creation of custom enzymes that will serve as tools of molecular surgery and molecular medicine.
08:45
Assay for Pathogen-Associated Molecular Pattern (PAMP)-Triggered Immunity (PTI) in Plants
0 Views •
Cited by 23 •
2009
A cell death-based assay for PTI in Nicotiana benthamiana plants is described.
FAQs
The beacon’s stem holds its fluorophore and quencher close enough to suppress fluorescence before target recognition. When a complementary nucleic acid sequence binds the loop, the hairpin opens and increases the distance between the labels. This structural change converts hybridization into an optical signal, allowing sequence recognition to be monitored through fluorescence rather than by directly observing the nucleic acid.
Stem and loop structure controls whether the beacon remains closed without its target and opens after complementary binding. A stable closed hairpin limits background fluorescence, while target recognition must be sufficient to produce opening and signal. Consequently, beacon design influences the balance between low background, target responsiveness, and the assay’s ability to distinguish the intended sequence.
Fluorescence increases when the beacon hybridizes with its intended sequence, so the signal is linked to sequence complementarity rather than simply to nucleic acid presence. This selectivity supports analysis of genetic variation and helps distinguish a chosen target from other sequences in a sample. The resulting signal is therefore interpreted in the context of the beacon’s designed target.
A useful signal depends on conditions that allow the beacon to remain quenched when unbound while permitting complementary target binding to open the hairpin. If these conditions do not support the intended balance, fluorescence may be weak or background may interfere with interpretation. Establishing suitable conditions is therefore essential for reliable sequence-specific measurement in samples or cells.
A typical workflow selects a beacon sequence complementary to the nucleic acid of interest, introduces the labeled hairpin into the sample or cellular context, and monitors fluorescence after potential target binding. The measured increase is then related to the presence or behavior of the intended sequence. This workflow supports real-time analysis because signal generation accompanies hybridization rather than requiring a separate endpoint observation.
Researchers can apply the assay when they need sequence-specific information about gene expression, genetic variation, infectious agents, or RNA dynamics. In biology, it can support genotyping, pathogen detection, and observation of RNA behavior in cells. Its value lies in combining fluorescence-based measurement with selectivity for a chosen nucleic acid sequence, allowing molecular events to be followed in relevant samples.