Molecular Beacons

Molecular Beacons are dual-labeled FRET probes incorporating a quencher and a fluorophore reporter molecule. They differ from Dual-labeled probes, due to the incorporation of a short (~5 b.p.) complementary sequence of bases at the 3' and 5' ends. These complementary sequences hybridize to form a stem structure which holds the reporter and quencher close together in space.  Also, Molecular Beacons do not rely on probe destruction from 5' exonuclease activity of Taq to generate its fluorescence, therefore, a post-PCR melt curve is possible.

Prior to amplification, the complementary bases of the stem hybridize forming the basic “stem-loop” structure of the Molecular Beacon. The stem raises the probe Tm and consequently Molecular Beacons can routinely discriminate between target sequences differing by a single nucleotide.  

Multiplex assays using Molecular Beacons are now possible that can detect several targets simultaneously using multiple spectrally resolved fluorescent probes.

Molecular Beacons are sold under license from the Public Health Research Institute, Newark, NJ.  For information on designing Molecular Beacons please refer to The Public Health Research Institute's Molecular Beacons website.

See also:
Dual-labeled BHQ® Probes | BHQplus Probes™ | Scorpion® Primers | Amplifluor® Primers | Plexor™ Primers | Dye Calibration Standards | Dyes from Biosearch Technologies