Precise quantitation and sensitive detection of copy number within genetic variations using ligation-mediated droplet digital PCR in plasma

The analysis of cancer-associated genetic copy number variations (CNVs) has been employed for cancer diagnostics, treatment, and prognostic assessments. The use of liquid biopsies to identify mutated gene biomarkers is of clinical significance to cancer diagnostics, but the methodology of the procedure remains challenging. In this study, using ligation-mediated droplet digital PCR for the highly sensitive and precise quantification of CNVs, we developed a system that enables precise copy number assessments in various biosamples at the single-molecule level at a sensitivity of 1 aM. By virtue of the assay, circulating target DNA in cell and complex plasma samples can be assessed, permitting a more detailed analysis of cancer-related genetic alterations. The proposed assay provides a useful tool to reveal how CNVs influence the occurrence of cancer in liquid biopsy samples, which is of clinical significance to cancer diagnostics and treatment.