Black Hole Quencher® Dyes |
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The Inescapable SolutionSM
Biosearch Technologies introduced the Black Hole Quencher® (BHQ®) dyes in 2000 and since then they have become the quencher of choice for qPCR probes and for other fluorescence-quenched probe applications. When fluorogenic dual-labeled probes were first introduced, quenchers were often a second reporter dye, typically TAMRA. The sensitivity of these probes, such as FAM-TAMRA, is limited because the fluorescence from TAMRA can leak into the channel meant to detect FAM fluorescence. Dark quenchers, which are dyes with no native fluorescence, offer a solution to this problem and DABCYL was the first widely-used dark quencher. DABCYL, however, has an absorption maximum at 474 nm, which is blue-shifted from the 520 nm FAM fluorescence maximum. Thus, DABCYL is not an optimal FRET quencher for most commonly used reporter dyes which have fluorescence above 490 nm.The BHQ dyes are true dark quenchers with no native emission due to their polyaromatic-azo backbone. Substituting electron-donating and –withdrawing groups on the aromatic rings produces a complete series of quenchers with broad absorption curves that span the visible spectrum: BHQ-0 (493 nm), BHQ-1 (534 nm), BHQ-2 (579 nm) and BHQ-3 (672 nm). These quenchers can be paired with all common reporter dyes to construct efficiently quenched qPCR probes for multiplexing assays. In addition to quenching by FRET, BHQ dyes have also been shown to efficiently quench fluorescence through static quenching via formation of a ground state complex with the reporter dye. Learn more about the difference between static and FRET quenching.
For protein labeling, we offer BHQ-10 (516 nm), which is water-soluble and available as a carboxylic acid and succinimidyl ester.
| Normalized absorption spectra of the BHQ dyes illustrate their range of quenching through FRET |
Download our Black Hole Quencher and Dye Selection Chart for more details about other offered dyes.
See Also: CAL Fluor® Dyes | Quasar® Dyes | Pulsar® 650 Dyes
