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

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. (C) 2008 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.