Scorpions™ Probes

Scorpions probes are highly sensitive, sequence-specific, bi-labeled fluorescent probe/primer hybrids designed for real-time quantitative PCR.

• When to Choose Scorpions Probes
• Benefits of Using Scorpions Probes
• Add LNA^® to Your Probe
• How Uni-Probe Scorpions Probes Work
• Product Features
• Guaranteed Yields
• Uni-Probe
• Bi-Probe

Choose Scorpions Probes for:

• SNP detection
• Allelic discrimination
• Pathogen detection
• Viral load quantification
• End-point genotyping
• Multiplex assay development

Because the probe and primer are incorporated into a single molecule, the reaction kinetics of this probe are extremely fast. The reaction leading to generation of a fluorescent signal is essentially instantaneous and occurs prior to any competing side reactions. This enables Scorpions probes to provide stronger signals, shorter reaction times, and better discrimination than other conventional bi-molecular mechanisms. It also allows for more reliable probe design.

Benefits of Using Scorpions Probes include:

• Increased specificity
• Fast amplicon detection
• Exceptional signal-to-noise (bi-probes typically yield stronger signal when compared to uni-probes)

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

back to top

How Uni-Probe Scorpions Probes Work

The Scorpions uni-probe consists of a single-stranded bi-labeled fluorescent probe sequence held in a hairpin-loop conformation with a 5' end reporter dye and an internal quencher dye directly linked to the 5' end of a PCR primer via a blocker. The blocker prevents the polymerase from extending the PCR primer.

At the beginning of the real-time quantitative PCR reaction, the polymerase extends the PCR primer and synthesizes the complementary strand of the specific target sequence. During the next cycle, the hairpin-loop unfolds and the loop-region of the probe hybridizes intramolecularly to the newly synthesized target sequence. Now that the reporter dye is no longer in close proximity to the quencher dye, fluorescence emission may take place. The fluorescent signal is detected by the real-time PCR instrument and is directly proportional to the amount of target DNA.

Product Features include:

• Available in lengths of 30 to 60 mers (uni-probe) and 15 to 45 mers (bi-probe)
• Simple pricing – HPLC purification and base charges are included
• Stringent quality control including electrospray mass spectroscopy
• Shipped within 7–10 business days
• 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.

back to top

The available fluorophore and quencher combinations are listed below. Scorpions Probes include a HEG (hexathylene glycol) blocker.

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 Scorpions probes and assays, submit your request at sigma.com/designmyprobe.

back to top