Novel Assays For CtDNA Enrichment And Analysis With The Employment Of Ccdb Reporter Genes

Objective: ctDNAs are precious material for early cancer diagnosis but the clinical value has been largely restrained by their extremely low copies as compared to the wild typed DNA fragments.The present study was designed to develop assays with high sensitivities and low false positives by enriching ctDNAs.Methods:Report gene ofccdbwas tested and integrated into assays for ct DNA enrichment.Theccdbgene was used for ctDNAs harboring nonsense mutations which their relevant wild typed alleles are nonsense transformable.The vector was developed and applied in mixed synthesized DNA oligonucleotides fragments.Results: WithKRAShotspot mutation as targets,1000 fold or higher enrichment was achieved by the new assay using mixed DNA oligonucleotides fragments.Application of the new assay inclinical samples confirmed their potential for genetic diagnosis.Conclusion: Two assays have been developed in enriching ctDNAs.One unique feature of the new assays is their high sensitivities and low false positives.The enrichment power of 1000 times and the serial combination of these assays with DNA sequencing render the new assays highly useful for early cancer diagnosis.