Controls to validate plasma samples for cell free DNA quantification

The present study presents external standardisation by spiking with non-human DNA fragments to control for loss of DNA during sample preparation and measurement. It also suggests a method to control for admixture of DNA from normal lymphocytes by utilizing the unique immunoglobulin gene rearrangement in the B-cells. The results show that this approach improves the quality of the analysis and lowers the risk of falsely increased values. In conclusion we suggest a new method to improve the accuracy of cfDNA measurements easily incorporated in the current technology.