The BiosearchTech Blog

Fluorescence Quenching Mechanisms for Dual-Labeled Probes

Posted on Wed, Jun 29, 2011 @ 07:44 AM

A "Referral from the Doctor" Blog Article-

Fluorescent probes are used in biochemical assays to monitor specific events such as binding, cleavage or conformational changes. Dual-labeled probes with a fluorophore and a quencher have many applications in genetic analysis. The efficiency of fluorescence quenching is very distance dependent – if the reporter fluorophore and quencher are far apart, there is fluorescence; if the reporter and quencher are close together in space, fluorescence is suppressed. Typically, the reporter and quencher are placed at specific sites in an oligonucleotide such that a change in their distance will produce a maximal change in fluorescence and effectively signal the event being monitored (often hybridization or nuclease activity). The oligonucleotide acts as a flexible tether linking the fluorescent reporter and quencher. Below, we present fluorescence quenching mechanisms for dual-labeled oligonucleotides in genetic analysis.

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Topics: Real-time PCR, Referral from the Doctor

Multiplexing with Xanthenes

Posted on Wed, Jun 08, 2011 @ 09:13 AM

A "Referral from the Doctor" Blog Article-

Quantitative real-time PCR (qPCR) was developed as a means to detect the presence of target nucleic acids and is routinely used to quantify gene expression through reverse transcription of RNA transcripts.  The detection method depends on a signaling molecule, often a dual-labeled oligonucleotide with a fluorophore (reporter) dye at the 5’ end and quencher dye at the 3’ end. The development of new reporter dyes, true dark quenchers and advancements in probe sophistication enable researchers to improve their genetic analysis.  One significant improvement is in the application of multiplexed qPCR to yield additional data and confidence in the results.

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Topics: Real-time PCR, Referral from the Doctor

qPCR Troubleshooting

Posted on Thu, May 05, 2011 @ 10:23 AM

A "Referral from the Doctor" Blog Article-

Quantitative real-time PCR (qPCR) is based upon the fractional cycle number at which a replicating sample of target DNA accumulates sufficient fluorescence to cross an arbitrary threshold. The threshold is either manually selected or auto-selected to fall several standard deviations above baseline fluorescence and below the plateau phase, where the amplification begins to attenuate. Typically, the threshold is adjusted to the mid-point of the exponential phase of the PCR, at a location suitable for all samples in the experiment. The CT (cycles to threshold) value for a given reaction is defined as the cycle number at which the fluorescence emission intersects the fixed threshold.

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Topics: Real-time PCR, Referral from the Doctor

Biosearch Technologies and Intelligent Medical Devices, Inc. (IMDx) Finalize cGMP Oligo Supply and Licensing Agreements for Molecular Diagnostic Testing (IVD) Products

Posted on Tue, Mar 15, 2011 @ 10:01 AM

Biosearch Technologies, Inc. (Biosearch), a leading supplier of sophisticated oligonucleotide components to the rapidly growing molecular diagnostics industry, and IMDx (privately held), a developer and manufacturer of innovative, clinically impactful molecular test solutions, today announced that Biosearch has licensed access to the BHQ®, CAL Fluor® and Quasar® patents to IMDx.  In addition, Biosearch will manufacture cGMP oligonucleotides for IMDx for use in human in-vitro diagnostics.

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Topics: Announcement, Molecular Diagnostics, Real-time PCR

Between ROX and a Hard Place

Posted on Wed, Nov 10, 2010 @ 09:12 AM

A "Referral from the Doctor" Blog Article-

ROX in qPCR

Quantitative real-time RT-PCR was developed as a means of quantifying gene expression either relatively or absolutely, with accurate and reproducible results. Despite advances in dye chemistries, variability continues to haunt research scientists.  One effort to reduce the observed variability between technical replicates was to include the ROX dye (5- or 6-carboxy-X-rhodamine) as a passive reference in the PCR master mix.

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Topics: Real-time PCR, Referral from the Doctor

Biosearch Technologies and DuPont Qualicon Finalize Agreements for Food Safety Dx

Posted on Fri, Oct 29, 2010 @ 09:24 AM

Biosearch Technologies, Inc. (Biosearch), a leading supplier of sophisticated oligonucleotide components to the rapidly growing molecular diagnostics industry, today announced that the company has licensed access to the BHQ®, CAL Fluor® and Quasar® patents to DuPont Qualicon.

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Topics: Announcement, Real-time PCR, Food Safety

Biosearch Technologies and Seegene Finalize Oligonucleotide Supply and BHQ®, CAL Fluor® and Quasar® Licensing Agreements

Posted on Wed, Oct 20, 2010 @ 08:12 AM

Biosearch Technologies, Inc. (Biosearch), a leading supplier of sophisticated oligonucleotide components to the rapidly growing molecular diagnostics industry, today announced that the company has licensed access to the BHQ®, CAL Fluor® and Quasar® patents to Seegene (KOSDAQ; Korea Securities Dealers Automated Quotations).

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Topics: Announcement, Real-time PCR

Biosearch Technologies Expands Licensing of QIAGEN Scorpions® Patents

Posted on Thu, Aug 12, 2010 @ 08:41 AM

Biosearch Technologies today announces that it has entered into a new license relationship with QIAGEN (NASDAQ: QIA, Frankfurt Prime Standard) providing broad commercialisation rights to Scorpions Primers.  This agreement allows Biosearch the right to manufacture, catalog, and sell Scorpions primer assays into the research, applied, and infectious disease testing markets.

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Topics: Announcement, Real-time PCR, Product Information

Taq Facts

Posted on Tue, Aug 03, 2010 @ 08:14 AM

A "Referral from the Doctor" Blog Article-

When the polymerase chain reaction (PCR) was first described, the Klenow fragment derived from the Escherichia coli DNA Polymerase I was the paramount enzyme for sequence extension. Due to its lack of stability at high temperature, it needs be replenished before each cycle. Upon the discovery of thermophilic bacteria which thrive at temperatures greater than 45 °C, heat-stable polymerases which function at higher temperatures were investigated in an effort to eliminate the need to replenish enzyme following each denaturation cycle.

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Topics: Real-time PCR, Referral from the Doctor

Pipetting for qPCR

Posted on Wed, Jun 09, 2010 @ 08:41 AM

A "Referral from the Doctor" Blog Article-

Research trends in laboratories today increasingly steer towards gene expression analysis and genetic testing, often in the form of qPCR. As reproducibility is essential to genetic research it is imperative that scientists know the fundamentals of micro-volume pipetting.

Forward and Reverse Pipetting: This discussion is limited to the use of manual pipettors. Electronic pipettors are capable of other pipetting techniques such as dispensing, sequential dispensing and diluting which are not discussed here.

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Topics: Real-time PCR, Lab Method, Referral from the Doctor

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About Biosearch Technologies

As the inventor of the BHQ dyes, Biosearch Technologies synthesizes sophisticated oligos for real time qPCR, molecular diagnostics, and more!  Visit our home page to view our products and services.

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