Dual-Labeled Probes

Whether your application is genotyping, gene expression, pathogen detection, or other, Sigma's wide selection of reporter and quencher dyes for quantitative PCR (qPCR) probes will support all real time and end-point detection chemistries.

• When to Choose Dual-Labeled Probes
• Benefits of Using Dual-Labeled Probes
• Add LNA^® to Your Probe
• How Dual-Labeled Probes Work
• Product Features
• Guaranteed Yields
• Spectral Properties Table

Choose Dual-Labeled Probes for:

• Gene expression
• Multiplex assay development
• Pathogen detection
• Viral load quantitation
• Microarray validation
• si/shRNA knockdown
• Gene copy determination
• Mutation detection
• Allelic discrimination
• SNP detection

Dual-labeled probes are highly sensitive, bi-labeled fluorescent probes and are designed to be sequence specific. They can be used with most real-time quantitative PCR instruments and multiplex analysis systems due to their straightforward design and the extensive range of fluorophores.

Benefits of Using Dual-Labeled Probes include:

• Design simplicity for sequence specificity
• Increased sensitivity
• Extensive availability of fluorophore combinations

Add LNA to Your Probe for:

• Increased thermal stability and hybridization specificity
• Greater accuracy in gene quantitation and allelic discrimination
• Easier and more sensitive probe designs for problematic target sequences

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How Dual-Labeled Probes Work

A dual-labeled probe is a single-stranded oligonucleotide labeled with two different dyes. A reporter dye is located at the 5' end and a quencher molecule located at the 3' end. The quencher molecule inhibits the natural fluorescence emission of the reporter dye by Forster-type energy transfer. The illustration below depicts the mechanism.

The primer is elongated by the polymerase and the probe binds to the specific DNA template, hydrolysis releases the reporter dye from the probe/target hybrid, causing an increase of fluorescence. The measured fluorescence signal is directly proportional to the amount of target DNA.

Product Features include:

• Available in lengths of 15–40 bases
• Simple pricing – HPLC purification and base charges are included
• Stringent quality control including electrospray mass spectroscopy
• Shipped within 3–5 business days for 6-FAM™, HEX™, or TET™ labeled
• Shipped in an amber tube to protect dye integrity
• Custom formats available (normalization, special plates, etc.) Sigma's probes are provided in a format to simplify your experimental planning

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The most common fluorophore and quencher combinations are listed below:

Label License Statement

Sigma^® is a licensed supplier of a variety of dyes and quenchers and continually adds to its portfolio of new chemistries. For assistance in the design of your dual-labeled probes and assays, submit your request at sigma.com/designmyprobe.

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