BHQ-2 acid | CAS 1214891-99-2

BHQ-2 acid is a fluorescence quencher designed for efficient signal suppression in fluorescence-based nucleic acid and FRET architectures. As a dark quencher, it is used to reduce background fluorescence by absorbing excitation energy from a nearby fluorophore, enabling distance-dependent or target-dependent fluorescence recovery in probe and biosensor formats. Its conjugation-ready carboxylic acid functionality supports incorporation into oligonucleotides and other labeled constructs used in molecular detection workflows.

1. Molecular Beacon Quenching

BHQ-2 acid is widely used as the quencher component in molecular beacons for fluorescence readouts in nucleic acid hybridization assays. Researchers incorporate BHQ-2 acid into the beacon design so that fluorescence from the attached reporter is suppressed in the unhybridized state and increases upon target binding and conformational change. This format is commonly applied in real-time fluorescence monitoring workflows where controlled on/off signaling is required for studying nucleic acid interactions, screening probe performance, and validating assay conditions.

2. Real-Time PCR Probe Suppression

BHQ-2 acid supports fluorescence signal control in oligonucleotide-based amplification assays, particularly in probe designs where a fluorophore is paired with a quencher to minimize background. In these workflows, the quencher placement enables efficient suppression of reporter emission until the probe is processed during amplification, producing a measurable increase in fluorescence for monitoring nucleic acid reactions. Molecular biology groups and assay developers use BHQ-2 acid to construct probe systems for method development, primer/probe optimization, and multiplex-compatible probe architecture planning.

3. FRET-Based Oligonucleotide Assays

BHQ-2 acid is frequently selected as a FRET quencher in nucleic acid assay designs that rely on proximity-dependent energy transfer between a donor fluorophore and an acceptor quencher. By positioning BHQ-2 acid within oligonucleotide constructs, developers can create distance-sensitive fluorescence responses that report on hybridization, strand displacement, or conformational switching events. Fluorescence chemistry teams use this quencher in probe development for mechanistic studies of nucleic acid dynamics and for building modular assay components that integrate with plate readers and fluorescence imaging instrumentation.

4. Signal-Controlled Biosensor Probes

BHQ-2 acid is also used in broader fluorescence biosensor development where quencher-fluorophore pairing is needed to manage baseline emission and define a measurable response upon target-driven structural or binding changes. In these applications, BHQ-2 acid is incorporated into oligonucleotide or biomolecule-linked probe scaffolds to create engineered signal suppression that improves interpretability of fluorescence readouts during assay optimization. Research groups developing fluorescence-based detection platforms use BHQ-2 acid to tailor probe geometry and quencher placement within modular sensor designs.