DiaCarta's Novel XNA Technology is a Game Changer for Sanger

Enabling Sanger Sequencing for Low Frequency Mutations Bypassing the Need for Next Generation Sequencing

PLEASANTON, Calif., Sept. 9, 2021 /PRNewswire/ -- DiaCarta Inc., a precision molecular diagnostics company and leading developer of novel oncology tests using liquid biopsy today announced the publication of a study entitled "Target Enrichment Enhances the Sensitivity of Sanger Sequencing for BRAF V600 Mutation Detection" in bioRxiv (https://www.biorxiv.org/content/10.1101/2021.08.14.456349v1) that demonstrates that enrichment of the mutant population in samples with DiaCarta's proprietary XNA based Molecular Clamping Technology improves Sanger sequencing to detect accurate mutations at 0.04% Variable Allele Frequency (VAF) compared to the >15% VAF that traditional Sanger sequencing needs.

Mutations in BRAF, the human gene encoding the protein B-Raf, a serine/threonine kinase, leads to unregulated cell growth, contributing to several types of cancers. V600E, a single nucleotide base substitution at exon 15, leads to severe over-activation of the protein resulting in 500-fold increased activity compared to the baseline. To counter the dysregulation in cell growth and downstream signaling resulting from BRAF mutations (V600E, V600R, V600D, V600M, V600G), several BRAF inhibitors have been developed. To initiated targeted therapy with these inhibitors, the complementary mutations need to be identified and this is often done using multiple in vitro molecular companion diagnostics tests, including Sanger sequencing. However, one caveat of this highly robust method is that it can only detect mutations accurately at 15% VAF or higher, thereby unable to provide the low limit of detection that is needed in companion diagnostics tests.

XNA enrichment is the process of using synthetic Xenonucleic acid molecular oligomers (XNA) in a tissue of blood sample to hybridize with target wild-type DNA sequences acting as molecular clamps, thereby blocking wild type sequencing, and only enabling the accurate amplification of mutant sequences, using quantitative real-time polymerase chain reactions (qPCR).

In this study, the sensitivity of Sanger sequencing using DiaCarta's QClamp BRAF V600 Enrichment Kit was evaluated. Results showed that enrichment of BRAF mutation containing samples with XNA was detectable on qPCR, the efficiency of Sanger sequencing was significantly improved, other BRAF V600 mutations were also detected and the enrichment of BRAF negative samples yielded no signal when analyzed by Sanger sequencing.

"XNA Molecular Clamping Technology is a validated method to block unwanted sequences during sequencing runs, enabling not only a cleaner template, but also yielding a more accurate result," said Aiguo (Adam) Zhang, CEO of DiaCarta. "BRAF mutations can often evade detection if present at low frequency, an oversight that can be easily corrected with XNA mediated template enrichment, a technology with a wide range of clinical applications. It is a game changer to bring Sanger sequencing up to the level of sensitivity equal to Next Generation Sequencing (NGS) at the fraction of the cost, since Sanger is still the gold standard in clinical testing."

About DiaCarta Inc.
DiaCarta is a molecular diagnostics company that has developed innovative technologies that transform patient care by providing effective precision diagnostics using liquid biopsy. In addition to its FDA EUA approved QuantiVirusTM SARS-CoV-2 Tests, DiaCarta offers a range of testing services, from single-gene QClamp® qPCR tests to its OptiSeq™ XNA-NGS panels. The company is well positioned as a leader in the new 'liquid biopsy' In Vitro Diagnostics field with high-precision detection of ctDNA. Its novel XNA technology provides high level of sensitivity as it clamps the wild-type sequence and amplifies the mutant target sequence. Using this technology, the company has developed its highly sensitive, early detection ColoScape™ Colorectal Cancer test using blood. Powered by its SuperbDNA™ technology that provides high level of detection by amplifying the signal and requiring no RNA/DNA extraction or amplification, the company has developed its revolutionary RadTox™ test that personalizes radiation therapy, mitigates adverse events, and enhances patient care. Based in Pleasanton, California the company is ISO certified, GMP-compliant and offers CLIA certified laboratory services to its customers. www.diacarta.com.

Contacts:
Corporate
Ram Vairavan, Ph.D.
SVP of BD
rvairavan@diacarta.com
760-402-6335

Media
Olipriya Das, Ph.D.
Russo Partners
olipriya.das@russopartnersllc.com
646-942-5588

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SOURCE DiaCarta Inc.