DusQ 2 phosphoramidite | CAS 374591-98-7

DusQ 2 phosphoramidite is a quencher phosphoramidite designed for incorporation into oligonucleotides during automated DNA/RNA synthesis. As a fluorescence-suppressing building block, it is used to control background signal in nucleic-acid fluorescence workflows, including hybridization-based assays and probe architectures where distance-dependent quenching is required. The phosphoramidite format supports straightforward placement at defined positions within primers, probes, or molecular beacon constructs for fluorescence readouts on common fluorescence instrumentation.

1. Molecular Beacon Fluorescence Control

DusQ 2 phosphoramidite is used to construct molecular beacons and related stem-loop oligonucleotide probes where a quencher placed near a fluorophore suppresses emission in the unbound state. Researchers incorporate DusQ 2 at specific sites to enable target-dependent fluorescence recovery upon hybridization, supporting fluorescence imaging and plate-based fluorescence assays that monitor nucleic-acid hybridization events. This quencher placement strategy is commonly adopted in assay development for sequence-specific monitoring using standard fluorescence readers and thermally cycled workflows.

2. Real-Time Nucleic Acid Assays

DusQ 2 phosphoramidite supports probe-based fluorescence assays in which quenching is engineered into the oligonucleotide reporter design. In these workflows, the quencher's role is to reduce signal from free probe and to shift the fluorescence response when the probe undergoes target-associated conformational or separation changes. Teams developing qPCR-like and isothermal amplification readouts often position quencher units at defined internal or terminal locations to tailor the fluorescence behavior of reporter oligos used with commonly available fluorescence detection platforms.

3. Oligonucleotide Probe Labeling Platforms

DusQ 2 phosphoramidite is employed as a site-specific quencher component for customized oligonucleotide probe sets used in genotyping, sequencing-by-hybridization, and multiplex fluorescence workflows. By integrating the quencher directly into the probe backbone during synthesis, assay developers can standardize probe architectures with consistent quencher-to-fluorophore spacing across batches. This approach is particularly useful when building multi-probe panels where controlled background suppression and defined probe geometry are important for robust fluorescence measurements.

4. FRET-Based Oligonucleotide Constructs

DusQ 2 phosphoramidite is also used in fluorescence resonance energy transfer (FRET) designs that rely on quencher-fluorophore coupling within nucleic-acid scaffolds. Researchers place DusQ 2 at selected positions relative to a donor/acceptor dye pair to engineer distance-dependent fluorescence changes during hybridization, strand displacement, or conformational switching. Such constructs are commonly used in fluorescence-based molecular sensing and nucleic-acid mechanistic studies where oligonucleotide architecture is the primary determinant of the fluorescence response.