Vity in the polymerase being used for amplification of target copies. The fluorophore, released from the target and separated from the quencher, is now highly fluorescent and ready for detection. Fluorophore/quencher pairs can be chosen based on spectral properties the emission of the fluorophore should overlap the absorption of the quencher. The quencher may absorb its partner’s fluorescence and emit the fluorescence at a new wavelength or, in the case of a non-fluorescent quencher, as heat. The new Epoch products offer two new fluorescent dyes, available immediately as phosphoramidites and supports, as shown in Figure 1. Their absorbance and emission characteristics are shown in Figure 2. Yakima Yellow has an absorption maximum at 530 nm and emission maximum at 549 nm, while Redmond Red’s absorption and emission maxima are at 579 nm and 595 nm, respectively. Over the years, the dabcyl molecule has proved to be an excellent universal nonfluorescent (dark) quencher for molecular beacon probes. In addition, dabcyl is a very stable molecule and synthesis of doublylabelled probes containing a dabcyl quencher is quite straightforward. The mechanism of quenching relies on the close proximity of the fluorophore to the dabcyl group, generally called static quenching, which is independent of spectral overlap between fluorophore and quencher. However in FRET probes, dabcyl’s ability to act as a dark quencher is limited by its absorption spectrum to use with dyes emitting at 400 550 nm. Other fluorescent quenchers can be used to cover a broad spectrum of dyes, but synthesis of the doubly-labelled probes is made much more difficult by the lack of stability of some of the potential candidates to the conditions of oligo deprotection. These probes are best prepared in a two-step process requiring post-synthesis conjugation of the second dye, usually with purification problems.405911-17-3 MedChemExpress The Eclipse Quencher from Epoch solves most of the problems inherent in the synthesis of molecular beacon and FRET probes.55721-31-8 Biological Activity The Eclipse molecule is highly stable and can be used safely in all common oligo deprotection schemes.
Measured in 0.1 M sodium phosphate. As indicated, Redmond Red is pH sensitive.PMID:28613558 Yakima Yellow is not and has the same extinction coefficient at pH 7 as pH 9. The QYs (quantum yield of fluorescence) were determined in 0.1 M Tris-HCl pH 7.4 relative to reference dyes using the dye-labeled T12 oligo. For Yakima Yellow, the reference dye was carboxy tetramethylrhodamine in methanol. For Redmond Red, the reference dye was sulforhodamine 101 in EtOH.
maximum for Eclipse Quencher is at 522 nm, compared to 479 nm for dabcyl. In addition, the structure of the Eclipse Quencher (Figure 1) is substantially more electron deficient than that of dabcyl and this leads to better quenching over a wider range of dyes, especially those with emission maxima at longer wavelength (red shifted) such as Redmond Red and Cy5. A simple experiment, using a molecular beacon probe, showed that quenching of the fluorescence of Cy5 was 53% more efficient with Eclipse Quencher than with dabcyl. Epoch researchers conducted a comparison1 of the quenching ability of the Eclipse Quencher relative to dabcyl in an enzymatic digestion assay designed to simulate the efficiency of quenching of FRET probes. Over the range of fluorophores from FAM (520 nm) to Cy5 (670 nm), Eclipse Quencher outperformed dabcyl in a measurement of signal to background ratio (signal, defined as fluorescence after digesti.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com