QIAamp Circulating Nucleic Acid Kit – cfDNA/cfRNA Isolation

For isolation of free-circulating DNA and RNA from human plasma or serum


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QIAamp Circulating Nucleic Acid Kit (50)

Cat. No. / ID:  55114

For 50 preps: QIAamp Mini Columns, Tube Extenders (20 ml), QIAGEN Proteinase K, Carrier RNA, Buffers, VacConnectors, and Collection Tubes (1.5 ml and 2 ml)
QIAamp Circulating Nucleic Acid Kit
Carrier RNA
The QIAamp Circulating Nucleic Acid Kit is intended for molecular biology applications. This product is not intended for the diagnosis, prevention, or treatment of a disease.

✓ 24/7 automatic processing of online orders

✓ Knowledgeable and professional Product & Technical Support

✓ Fast and reliable (re)-ordering


  • Concentration of nucleic acids, with high input and low elution volumes
  • Efficient recovery of fragmented DNA and RNA
  • No organic extraction or ethanol precipitation
  • Removal of contaminants and inhibitors
  • Vacuum manifold required to process samples, e.g. QIAvac 24 plus

Product Details

The QIAamp Circulating Nucleic Acid Kit greatly simplifies concentration and purification of free-circulating DNA and RNA from plasma or serum.

The kit can be automated on the QIAcube Connect.


Analysis of tumor-specific extracellular DNA fragments and mRNAs in the blood can enable specific detection of tumor types from a simple blood sample. These circulating nucleic acids are present in serum or plasma usually as short fragments, <1000 bp (DNA) or <1000 nt (RNA). In addition, miRNAs, as small as 21 nt, have the potential to provide biomarkers for certain cancers and disease states.

The QIAamp Circulating Nucleic Acid Kit enables efficient purification of these circulating nucleic acids from human plasma or serum and other cell-free body fluids. Efficient purification with reproducible yields provides a representative population of the circulating nucleic acids in blood (see figure " Reproducible recovery of circulating DNA"). Tube extenders and vacuum processing on the QIAvac 24 Plus enable starting sample volumes of up to 5 ml, and flexible elution volumes between 20 μl and 150 μl allow concentration of nucleic acid species that are present in low concentrations. The kit provides advanced technology of selective binding to a silica-based membrane for improved recovery of fragmented nucleic acids (see figure " Improved recovery of fragmented DNA").

Purification of circulating RNA, without copurification of DNA, is possible with DNA digestion using the RNase-Free DNase Set. A specialized protocol provides highly efficient purification of small RNA, such as miRNAs (see figure " Efficient purification of circulating miRNA"). Methylated DNA can be efficiently purified using the QIAamp Circulating Nucleic Acid Kit. The purified DNA maintains its methylation, allowing bisulfite conversion for analysis of the methylation state (see figure " Efficient recovery of methylated DNA").

The purified and concentrated circulating DNA and RNA is free of proteins, nucleases, and other impurities, and is ready to use in wide range of downstream applications, including:

  • PCR and quantitative real-time PCR and RT-PCR
  • Biomarker research and validation for blood-based cancer detection
  • Viral nucleic acid detection
See figures


The QIAamp Circulating Nucleic Acid Kit simplifies isolation of circulating DNA and RNA from plasma or serum. No phenol–chloroform extraction is required. Nucleic acids bind specifically to the QIAamp Mini column, while contaminants pass through. PCR inhibitors, such as divalent cations and proteins, are completely removed in 3 wash steps, leaving pure nucleic acids to be eluted in a buffer provided with the kit. The QIAamp Circulating Nucleic Acid technology yields circulating DNA and RNA from human plasma, serum, or urine.

The QIAamp Circulating Nucleic Acid Kit combines the selective binding properties of silica-based membrane with flexible elution volumes between 20 and 150 μl. Circulating RNA can be purified with DNA digestion using the RNase-Free DNase Set.


The QIAamp Circulating Nucleic Acid procedure includes 4 steps (lyse, bind, wash, and elute) that are carried out using QIAamp Mini columns on a vacuum manifold. The simple procedure is highly suited for simultaneous processing of multiple samples, providing nucleic acids in less than 2 hours per 24 samples. If the QIAamp Circulating Nucleic Acid Kit is used for isolation of viral RNA and DNA, the performance cannot be guaranteed for every virus species and must be validated by the user.


The QIAamp Circulating Nucleic Acid Kit efficiently purifies and concentrates free-circulating DNA, RNA, miRNA, and viral nucleic acids from starting materials that contain low concentrations of mostly fragmented DNA and RNA (typically 1–100 ng/ml circulating DNA in human plasma). Starting sample volumes can be up to 5 ml.

The QIAamp Circulating Nucleic Acid Kit purifies and concentrates nucleic acids from the following sample types:

  • Human plasma
  • Serum
  • Urine

Supporting data and figures


ApplicationsPCR, real-time PCR
CE/FDA/IVD compatible-
TechnologySilica technology
Purification of total RNA, miRNA, poly A+ mRNA, DNA or proteinFree-circulating DNA, RNA and miRNA, viral DNA, viral RNA
Time per run or per prep<2 hour for 24 preps
FormatQIAamp Mini Columns
Main sample typeSerum, plasma
ProcessingManual (vacuum)
Sample amount1-5 ml
Elution volume20–150 µl
YieldVaries, due to donor-to-donor variations and disease status


Brochures & Guides (1)
Kit Handbooks (1)
For concentration and purification of free-circulating DNA and RNA from human plasma or serum
Safety Data Sheets (1)
Application Notes (1)
Digital PCR (dPCR) is a powerful technique that detects and quantifies ultra-rare mutations in a high background of wild-type cfDNA down to 0.1% variant allele frequency. Here, we describe end-to-end manual and automated workflows that enable accurate detection and absolute quantification of ultra-rare PIK3CA variants in cfDNA using the QIAcuity Digital PCR System.
Certificates of Analysis (1)


Noninvasive whole-genome sequencing of a human fetus.
Kitzman JO; Snyder MW; Ventura M; Lewis AP; Qiu R; Simmons LE; Gammill HS; Rubens CE; Santillan DA; Murray JC; Tabor HK; Bamshad MJ; Eichler EE; Shendure J;
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Non-invasive prenatal measurement of the fetal genome.
Fan HC; Gu W; Wang J; Blumenfeld YJ; El-Sayed YY; Quake SR;
Nature; 2012; 487 (7407):320-4 2012 Jul 19 PMID:22763444
Frequent methylation and oncogenic role of microRNA-34b/c in small-cell lung cancer.
Tanaka N; Toyooka S; Soh J; Kubo T; Yamamoto H; Maki Y; Muraoka T; Shien K; Furukawa M; Ueno T; Asano H; Tsukuda K; Aoe K; Miyoshi S;
Lung Cancer; 2011; 76 (1):32-8 2011 Nov 1 PMID:22047961
Implementing prenatal diagnosis based on cell-free fetal DNA: accurate identification of factors affecting fetal DNA yield.
Barrett AN; Zimmermann BG; Wang D; Holloway A; Chitty LS;
PLoS One; 2011; 6 (10):e25202 2011 Oct 4 PMID:21998643
IgH gene rearrangements as plasma biomarkers in Non- Hodgkin's lymphoma patients.
He J; Wu J; Jiao Y; Wagner-Johnston N; Ambinder RF; Diaz LA Jr; Kinzler KW; Vogelstein B; Papadopoulos N;
Oncotarget; 2011; 2 (3):178-85 2011 Mar PMID:21399237


What can be used as an alternative to the A260 measurement for quantification of small amounts of RNA and DNA?

Small amounts of RNA and DNA may be difficult to measure spectrophotometrically. Fluorometric measurements, or quantitative RT-PCR and PCR are more sensitive and accurate methods to quantify low amounts of RNA or DNA.

Fluorometric measurements are carried out using nucleic acid binding dyes, such as RiboGreen® RNA Quantitation Reagent for RNA, and PicoGreen® DNA Quantitation Reagent for DNA (Molecular Probes, Inc.).

FAQ ID -728
What is the average amount of DNA and RNA present in 1 ml normal serum?

According to an Interview with Professor Dennis Lo published in QIAGEN News Molecular Diagnostics, Issue No. 5, 2002, healthy individuals have about 500-1000 genome equivalents (DNA) per ml serum/plasma.

For free-circulating DNA in plasma, the concentration can range from 1–100 ng/ml in healthy individuals.

FAQ ID -635