PointSuppressor™
Wild Type Suppression

SYNTHETIC NUCLEOTIDES AND METHODS FOR SELECTIVELY AMPLIFYING ALLELES
U.S. Provisional Patent Filed 02FEB2021.

PointSuppressor™ – the new standard in rare allele detection. Next-Generation Sequencing (NGS) based liquid biopsy applications – whether to detect cancer, transplant rejection, fetal DNA, or antimicrobial resistance – require a tremendous number of sequence reads to find rare alleles. Most of these sequencing reads are uninformative, for instance, background wild type sequences in the case of mutation detection in cancer. PointSuppressor™ technology suppresses these uninformative reads without interfering with amplification of the desired targets. The assay footprint is kept short since no blockers are used. Accuracy is extremely high since no mutant sequences are ever introduced into the reaction.

PointSuppressor™
Wild Type Suppression

SYNTHETIC NUCLEOTIDES AND METHODS FOR SELECTIVELY AMPLIFYING ALLELES
U.S. Provisional Patent Filed 02FEB2021.

PointSuppressor™ – the new standard in rare allele detection. Next-Generation Sequencing (NGS) based liquid biopsy applications – whether to detect cancer, transplant rejection, fetal DNA, or antimicrobial resistance – require a tremendous number of sequence reads to find rare alleles. Most of these sequencing reads are uninformative, for instance, background wild type sequences in the case of mutation detection in cancer. PointSuppressor™ technology suppresses these uninformative reads without interfering with amplification of the desired targets. The assay footprint is kept short since no blockers are used. Accuracy is extremely high since no mutant sequences are ever introduced into the reaction.

 

PointSuppressor™ (PSP) is a transformational technology for primer-based applications requiring a more scalable or sensitive assay.  

 

PointSuppressor™ (PSP) is a transformational technology for primer-based applications requiring a more scalable or sensitive assay.

Suppression of Unwanted Reads

Applying PSP to a standard PCR assay suppresses the wild type signal enabling sensitive detection of the mutant signal.

The power of our PointSuppressor™ technology is evident even using a low-tech readout like Sanger Sequencing.

In the figure, normal PCR conditions were used for the top two Sanger sequencing traces with the wild type “G” signal (in black) dominating the mutant “A” signal (in green).  The bottom two traces show results using PointSuppressor technology under otherwise identical reactions. A remarkable turnabout is seen, with the mutant “A” signal becoming the dominant signal. No extra processing is required, just simple additions to the PCR mix. 

Extraordinary Sensitivity

PointSuppressor™ technology suppresses unwanted reads without interfering with the detection of desired targets. In this example, DNA containing wild type KRAS (a “G” at nucleotide position c.38) is used in three-fold serial dilutions of mutant (A) DNA. Even with only two molecules present, a strong “A” signal is still seen against a suppressed background of 2,998 wild type “G” molecules. Samples diluted to below one mutant molecule; wild type only; and no template controls, did not yield enough PCR product to meet the minimum required for Sanger sequencing.

PointSupressor Wild Type Suppression Example Data

An Internal Counting Standard (iCS)

Although undesired reads can be virtually eliminated without compromising the detection of desired targets, it’s useful if we don’t do so entirely. For instance, in cancer mutation detection, a low level of wild type sequence demonstrates that the specific assay worked. It also provides an internal counting standard (iCS) to facilitate comparison between specimens collected at different times. PointSuppressor™ is absolutely unique in its ability to suppress unwanted signals to a “tunable” level – one that dramatically reduces costs, but still serves our need for controls and standards.
PSP reactions can be tuned to allow a small number of wild type sequences through to demonstrate the reaction worked and provide an internal counting standard.

Biomarker Detection

PointSuppressor™ technology is ideally suited for biomarker detection in your clinical development program. Click here to access your results or to register your company or contact us.