Coherent Quenching of a Fluorophore for the Design of a Highly Sensitive In-Stem Molecular Beacon

摘要

Fluorescence-labeled oligonucleotides provide powerful tools for highly sensitive, sequence-specific detection of target DNA/RNA. A variety of fluorescent probes have been designed for purposes such as genotyping of individuals, identification of pathogens, and real-time monitoring of mRNA within cells. One practical problem with the use of these fluorescent probes is background emission intensity in the absence of the target, because background emission, as well as scattered light of excitation due to a small Stokes shift, critically affects probe sensitivity. Suppression of background emission is particularly important for the design of a highly sensitive molecular beacon (MB); that is, a hairpin oligonucleotide dual-labeled at both 5'- and 3'-termini with a fluorophore and a quencher.