How The AccufyDx Technologies Outperform Current Ones

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Next-generation sequencing (NGS) has transformed clinical medicine and basic research. Despite its ability to produce hundreds of billions of nucleotides of DNA sequence in a single experiment, the technology has an error rate of approximately 0.1%- 1% depending on various factors, leading to millions of sequencing mistakes. 

Multiple molecular barcode-tagging technologies have been developed to address the challenge.  The use of molecular barcodes to tag one strand or both strands of the original template molecules was developed to address various challenges in detecting rare mutations. By employing molecular barcoding, redundant sequencing of the PCR-generated progeny of each tagged molecule is performed, making it easier to identify sequencing errors as genuine mutations are expected to be present in all progeny sequences tagged with the same molecular barcode. 

A particular method has been developed to append unique molecular identifier (UMIs) to both ends of each strand of the original dsDNA molecules.  After sequencing, only DNA mutations that are detected in all or almost all sequencing reads containing the same UMI in both stands of a DNA template are considered genuine. This and a more recently developed duplex sequencing strategy have achieved the lowest sequencing error rate described so far.  

In comparison, the Accufy method outperforms the two abovementioned tagging technologies in that the resulted DNA library made via Accufy technology featured the highest percentage DNA molecules that carry the UMIs.  Data are available upon request.  

Current target enrichment methodologies include amplicon-based PCR, hybrid capture and anchored PCR.  PCR approach is simple and fast; however, one specific molecular barcode can be appended only to one strand, and consequently the sensitivity and specificity of detecting rare variants by PCR-based approach were greatly compromised compared to approaches in which molecular barcodes/UMIs were appended to both strands of the original template molecules.  In addition, PCR approach requires two loci-specific primers for PCR amplification of target DNA molecules and thus this PCR approach cannot be used for identification of gene fusions with novel fusion partners. 

Hybrid capture approach requires larger input DNA materials, long incubation time and poor DNA recovery for target-enrichment, limiting the use of the hybrid capture technology in the clinical DNA testing fields that require high efficiency and sensitivity of detecting rare variants in small target regions, especially when starting materials are limited especially in the context of liquid biopsy and MRD.  

Another bottleneck in analyzing target-specific DNA lies in the lack of target enrichment technology that preserve the in-situ genetic and epigenetic information.

The Accufy NGS target enrichment technology is developed to address both the need for operation ease in clinical diagnostic lab and the need to preserve multiomic information of DNA molecule.   The Accufy sample enrichment can be performed as short as 4 hours.  In addition, the enriched target samples can be directly analyzed for epigenetic alterations and genetic mutations with the confidence that the epigenetic and genetic alterations revealed are on the same DNA molecules.