Circulating cell-free DNA
Liquid biopsy

Circulating cell-free DNA

Innovation is in the blood

Cell-free DNA (cfDNA) carries real-time information that can be used to detect and monitor biomarkers of cancer and other diseases in a simple blood test.

cfDNA is often found in low concentrations with rare mutations or in a fragmented condition, and you need reliable tools that give you confidence in the signal you detect. Whether you work in biomarker discovery, transplant or NIPT research, our products for cfDNA isolation and analysis give you the reliable results you need.

Innovation is in the blood
Did you know? cfDNA typically circulates in fragments that range from 120–220 base pairs, with a predominant fragment size of 170 base pairs. This corresponds to the length of DNA that can wrap around a nucleosome (147 bp), plus an additional stretch of DNA that links two nucleosome cores. The half-life of cfDNA in blood ranges from 15 minutes to 2.5 hours, and when it originates from tumor cells, it is referred to as circulating tumor DNA (ctDNA).

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Comprehensive workflow solutions starting with blood collection and stabilization along the molecular analysis workflow from dedicated cfDNA preparation to integrated data analysis solutions for various applications by next-generation sequencing or digital PCR, scalable to your sample volume, throughput or outsourcing needs.

Products along the workflow

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With our Genomic Services, you can:
  • Extend your in-house resources quickly and conveniently
  • Ensure your data is high quality using our expertise
  • Get support with just the time-consuming parts of your project or with your entire Sample to Insight journey
  • Benefit from expert consultation and make the best decisions to achieve your goals
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Learn more about the options available to you and consult with our experts.
A range of different manual or automated cfDNA isolation systems are available to suit different starting volume, processing time and throughput needs. To help you choose the best combination of products to isolate cfDNA for your applications, see the graphics, or download the brochure that also includes information on cfDNA analysis by dPCR and next-generation sequencing and data interpretation systems.

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Select products for diagnostic applications

cfDNA isolation from large starting volumes

The concentration of cfDNA in biological fluids such as plasma or urine is usually low and varies considerably between individuals, usually from 1–50 ng/ml. Typically, input volumes of 4 ml are used, which corresponds to the total plasma volume from one blood collection tube. Depending on the target DNA, the application, and the sensitivity of the downstream assay, the sample input volume needed can vary from 1 to 10 ml. We provide a range of cfDNA purification kits that offer fast workflows and unmatched cfDNA concentrations from varying sample inputs for high sensitivity in downstream NGS and PCR analyses.

Imagine analyzing a cfDNA eluate containing a very rare event. You might want to get the maximum possible input into the cell-free DNA analysis workflow. Combine up to 8 ml plasma sample processing on EZ2 Connect with high-volume eluate loading on QIAcuity.

Have you considered the power of two?

EZ2 Connect and QIAcuity for cfDNA analysis

If you isolate cfDNA from a larger volume of serum or plasma and then use large-volume eluate loading with a highly sensitive detection method like digital PCR, you can load more and see more. Processing larger volumes gets more template cfDNA and dPCR will detect more mutations. You can achieve this goal by combining EZ2 Connect for easy a sample processing with the QIAcuity dPCR system.

You can now combine a fully automated and convenient high-volume sample processing on the EZ2 Connect with fast and sensitive ultra-low mutation detection using digital PCR on the QIAcuity.


See for yourself
The best way to see the power of two is to try it out yourself. Complete the form to request a demo in your lab.

Learn from the experts

  • Cell-free DNA analysis – status and outlook
    Ellen Heitzer presents several studies evaluating various workflows for cfDNA analysis. Issues hampering the clinical implementation of cfDNA analysis and possible ways forward are discussed.
  • Standardization in cell-free DNA sample processing
    A deep dive into cell-free DNA: learn about a true walkaway solution for automated isolation from up to 8 ml. And hear from Constanze Kindler, Ph.D. about challenges and new solutions for analyzing cfDNA from up to eight milliliters of blood.
  • cfDNA collection/stabilization and sample preparation
    Martin Schlumpberger and our panel of experts answer your questions on how to collect, stabilize and process your samples when working with cfDNA. Get answers, tips and tricks to ensure a successful start to your analysis.
  • cfDNA Digital PCR
    Özlem Karalay and our dPCR experts dive deep into the exciting analysis opportunities offered by dPCR technologies. Check out how sensitive and accurate your cfDNA analysis can be.
  • cfDNA NGS (SNV, CNV, methyl markers) and data analysis
    Want to use the power of NGS to analyze your samples? Peter Hahn and our next-generation sequencing experts answer all your questions in this final panel discussion on cfDNA analysis.
  • Ellen Heizer
    Cell-free DNA analysis – status and outlook
  • Standardization in cell-free DNA sample processing
    Standardization in cell-free DNA sample processing
  • cfDNA collection/stabilization and sample preparation
    cfDNA collection/stabilization and sample preparation
  • Oezlem Karalay
    cfDNA Digital PCR
  • Peter Hahn
    cfDNA NGS (SNV, CNV, methyl markers) and data analysis


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