An Elegant Biosensor Molecular Beacon Probe: Challenges and Recent Solutions
Figure 2
Examples of fluorescent reporters. (a) TaqMan probe. Fluorophore- and quencher-labeled stem-free oligonucleotide hybridizes to a single-stranded DNA amplicon and becomes cleaved by the 5′–>3′ exonuclease activity of DNA polymerase during elongation step of rtPCR [16–18]. (b) Chemical autoligation assay [18–20]. An oligonucleotide with a fluorophore and a quencher hybridizes to the analyte in proximity to the second oligonucleotide probe equipped with a nucleophilic reactive group. Chemical reaction of the two oligonucleotide probes results in both ligation of the oligonucleotides and detachment of the quencher. The unquenched fluorophore produces bright fluorescence.
