An Auto-Reading probe system for detecting deletion mutations In liquid biopsy with direct quantification of mutation abundance.

Background: Deletion mutations have been confirmed to be closely related to the occurrence and progression of different hereditary diseases and tumors. Specifically, the deletion of a small number of bases is more challenging to be captured and differentiated. In non-invasive prenatal testing (NIPT) and liquid biopsy targeting circulating tumor DNA, obtaining accurate mutation abundance in targeted DNA is a crucial step in the detection process. However, the quantification of mutation abundance with existing methods is not accurate enough. Results: Herein, we developed the " Auto-Reading" probe detection system based on our previous work. Through theoretical modeling and experimental calculations, we verified the successful application of our system in NIPT and early cancer diagnosis, enabling effective discrimination of different mutant abundances. Significance: Our method overcomes the interference of reaction concentrations on signal detection, allowing direct quantification of mutation abundance without the need for purification of PCR products. The detection system is cost-effective and feasible for laboratory use. We believe the system will facilitate broad applications in mutation detection.