The increased use of cfDNA-based assays in the clinical oncology setting faces a challenge: the lack of large volumes of patient plasma with well-defined genetic content suitable for establishing true plasma-based reference standards and controls. Unknown genetic background or trace amounts of genomic fragments can interfere with the analysis of ctDNA. As shown in figure below, the extracted cfDNA represented by the 170bp peak, is often associated with a significant number of large genomic DNA fragments that can interfere with the cfDNA assay.
Anchor Molecular has developed technology that specifically removes DNA from plasma without affecting the rest of the composition. The treated plasma has less than 10 pg/ml (less than 1% of the original DNA content) extracted with a commonly used cfDNA extraction kit.
Afterwards, short DNA fragments containing defined genetic composition are spiked into the plasma, shown in figure below.
The spiked DNA shows good linearity and stability.