Circulating DNA Quantification

Circulating DNA, also named cell-free DNA (cfDNA), is a series of highly fragmented DNA that is present in the blood circulation and other body fluids of human and is free of extracellular. In certain situations, such as cancer patients, pregnant women, patients undergoing organ transplants, etc., a small number of circulating DNA from “heterologous” cells can be used as markers for genetic testing [1]. Large quantity of autologous cell-free DNA reflects abnormal cell death. Autologous cell-free DNA quantification can be used for the diagnosis and monitoring of related diseases. The “liquid biopsy” technology based on circulating DNA detection has received great attention in many aspects such as prenatal diagnosis, tumor screening, early diagnosis, and treatment monitoring, and prognosis evaluation. Because of its extremely low content, a very large number of studies have been done to develop various methods for quantitative detection [1, 2]. At the moment circulating DNA quantitative detection still faces challenges such as the lack of specification, precision, and standardization in detection processes.