Custom quencher-modified oligos and dual-labeled probes using BHQ, Iowa Black, Dabcyl, QSY, ATTO Quenchers and fluorescent acceptors for qPCR, ddPCR, molecular beacon, TaqMan and FRET workflows.
Bio-Synthesis supports custom quencher-modified oligonucleotides, dual-labeled qPCR probes, TaqMan-style hydrolysis probes and molecular beacon designs for sensitive fluorescence suppression, clean baseline control and multiplex assay compatibility.
Dark quenchers such as BHQ-1/BHQ-2/BHQ-3, Iowa Black FQ/RQ, Dabcyl, QSY, ATTO Quenchers and DYQ quenchers absorb donor emission without adding stray fluorescence, making them preferred for qPCR, ddPCR and multiplex probe panels.
Fluorescent acceptors such as TAMRA, ROX and Cy5 remain useful for FRET-based designs, calibration channels and specialized probe architectures where acceptor emission provides additional readout information.
BHQ-1, Iowa Black FQ, Dabcyl, QSY 7, ATTO 540Q
BHQ-2, Eclipse, ATTO 580Q, DYQ-4, DYQ-425
BHQ-3, Iowa Black RQ, QSY 21, ATTO 612Q, DYQ-660
QSY 35, DYQ-700 and extended red/NIR quenchers
Select the donor dye/channel to view commonly recommended dark quenchers and alternate quenchers.
Fast starting points for common qPCR and probe designs.
Note: Pairings are practical starting points. Final selection should consider probe length, fluorophore position, instrument channel, multiplex design and reaction conditions.
This table is intentionally preserved as the primary selection guide. Pair BHQ-class, Iowa Black, Dabcyl, QSY, ATTO and DYQ quenchers with common donor dyes for TaqMan probes, molecular beacons and multiplex qPCR designs.
Choose a quencher with absorption overlap across the donor emission channel.
Technical notes: BHQ-1 typically covers green donors, BHQ-2 covers orange-red donors, and BHQ-3 covers far-red donors. Dark quenchers minimize bleed-through and simplify multiplex qPCR/ddPCR. Probe architecture, 5′/3′ placement, internal quenchers and spacer length can affect on/off ratio.
Fluorescent acceptors can be useful for FRET pairs, calibration dyes or specialized probe designs that benefit from acceptor emission.
Use when acceptor emission is helpful rather than a source of cross-talk.
Design note: FRET efficiency depends on donor-acceptor spectral overlap, distance and orientation. Acceptor emission can aid troubleshooting but may add a detection channel in multiplex assays.
Start with donor emission, then refine by instrument channel, probe architecture and multiplex requirements.
Pick a quencher whose absorption overlaps the donor emission peak.
Prefer dark quenchers for multiplex qPCR and ddPCR panels.
Adjust spacer length, probe length and internal quencher position for on/off ratio.
Align donor and acceptor channels with qPCR, ddPCR or imaging filters.
Quencher-modified oligos are used when fluorescence must turn on only after hybridization, cleavage, displacement or conformational change.
Dual-labeled probes for real-time PCR, ddPCR and multiplex detection.
Stem-loop probes with quenched baseline and target-triggered fluorescence.
Donor-acceptor designs for distance-sensitive and conformational readouts.
Dye-quencher pairing for FAM/HEX/ROX/Cy5-style channel sets.
Allele-specific probes requiring low background and precise channel separation.
Probe designs for development-stage molecular diagnostics and detection platforms.
Explore connected probe and detection services.
Include sequence, donor dye, quencher, probe type, scale and QC.
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