Advances in molecular beacon technology and its application.

Tyagi and Krammer designed a new fluorescent probe in 1996 that specifically identifies
nucleic acid
sequences, which fluorescence is fluorescent by a change in composition that occurs after hybridization with nucleic acid target molecules, and they named it Molecular Beacon.
molecular beacon has low background signal, high sensitivity, strong specific recognition, simple operation, do not need to be separated from the unresponsive probe can be detected in real time, can be used for live analysis and other advantages.
is
widely used
biochemical
research
clinical diagnosis in the field of biochemistry.structure
(1) ring region of
molecular beacons (15 to 30 base sequences in length, can be specifically combined with the target sequence)
(2) beacon stem stem area (length 5 to 8 bases of complementary sequences, resulting in hairpin structure, independent of the target sequence)
(3) fluorescent group and sudden destruction base Clusters (connected by co-priced keys at the end of the stem area, fluophoophoophoric group joined at the 5'-end of the beacon molecule, annihilation group joined at 3'-end)


the addition of the target sequence, the molecular beacon and the fully complementary target sequence form a rigid and more stable double-stranded hybrid, which increases the distance between the fluorescent and annihilation groups, preventing freT from occurring and the fluorescence recovery.design of
molecular beacons
sequence length (ring sequence is more than twice as long as stem sequence, stem sequence can not be too long or too short)
the content of G and C in stem sequence can not be too high
5'-end The first base is best not to select G
because the subject
DNA
or RNA is a large molecule, there is distortion, so choose the outer base sequence of the object under test, that is, the easy-to-access sequence to design the beacon.
.