Molecular Beacons: Probes That Fluoresce Upon Hybridization

Department of Molecular Genetics, Public Health Research Institute, New York, NY 10016, USA.
Nature Biotechnology (Impact Factor: 41.51). 04/1996; 14(3):303-8. DOI: 10.1038/nbt0396-303
Source: PubMed


We have developed novel nucleic acid probes that recognize and report the presence of specific nucleic acids in homogeneous solutions. These probes undergo a spontaneous fluorogenic conformational change when they hybridize to their targets. Only perfectly complementary targets elicit this response, as hybridization does not occur when the target contains a mismatched nucleotide or a deletion. The probes are particularly suited for monitoring the synthesis of specific nucleic acids in real time. When used in nucleic acid amplification assays, gene detection is homogeneous and sensitive, and can be carried out in a sealed tube. When introduced into living cells, these probes should enable the origin, movement, and fate of specific mRNAs to be traced.

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    • "The Molecular beacon (MB) usually is constructed with 25-35 nucleotides and a specific stemloop conformation that allow the maintenance of the fluorescence by resonance energy transfer (RET) (Tyagi et al. 1996). When the MB hybridizes with the target, there is a change in the loop conformation, resulting in an increase of the distance between the fluorophore and the quencher, breaking the FRET, allowing the fluorescence detection (Tyagi et al. 1996) The MB technology applied to environmental virology is still recent and limited, but this method was reported for virus detection, showing an specific binding on viral DNA in clinical samples (Dunams et al. 2012). "
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    • "The quencher can be coupled to a second complementary oligonucleotide, which is displaced upon binding to the target sequence (Morrison et al., 1989). In so-called molecular beacons, the quencher is coupled to the same oligonucleotide (Tyagi and Kramer, 1996; Vargas et al., 2005). Molecular beacons contain small complementary sequences on both ends, thereby forcing the unbound molecule into a hairpin configuration, in which the dye and the quencher are kept in close proximity. "
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