Unequal representation of different unique genomic DNA sequences in the cell-free plasma DNA of individual donors.

ABSTRACT

OBJECTIVES: To assess whether different genomic cell-free DNAs are equally abundant in the plasma of individual donors, and any relationship between DNA methylation and representation in plasma. DESIGN AND METHODS: The concentrations of DNA in plasma were determined by real-time PCR. RESULTS: Different DNA sequences were not equally represented. The relative abundances were similar in different donors. CONCLUSIONS: Different DNA sequences are not equally abundant in plasma, with no relationship between DNA methylation and abundance.