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, we establish ligation-mediated droplet digital PCR for the highly sensitive and precise quantification of CNVs which enables precise copy number assessments in various biosamples at the single-molecule level. In virtue of its excellent performances, circulating-free target DNA in cell or 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.