Circulating Dna
Circulating Dna - Related Videos
06:53
Detection and Monitoring of Tumor Associated Circulating DNA in Patient Biofluids
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Cited by 7 •
2019
Here, we present a protocol to detect tumor somatic mutations in circulating DNA present in patient biological fluids (biofluids). Our droplet digital polymerase chain reaction (dPCR)-based method enables quantification of the tumor mutation allelic frequency (MAF), facilitating a minimally invasive complement to diagnosis and temporal monitoring of tumor response.
08:29
Profiling Epidermal Growth Factor Receptor DNA Mutations in Circulating Rare Cells Using a Cell Isolation System and Droplet Digital PCR
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2026
Here we present a protocol to illustrate the isolation of rare cancer cells from a contrived sample containing whole blood and spiked in lung cancer cells. The protocol utilizes a semi-automated, label-free cell isolation platform. Enriched cells are subsequently analyzed for epidermal growth factor receptor mutations using droplet digital PCR.
07:37
Circulating MicroRNA Quantification Using DNA-binding Dye Chemistry and Droplet Digital PCR
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Cited by 9 •
2016
A sensitive and accurate method for cell-free microRNAs quantification using a dye-based chemistry and droplet digital PCR technology is described.
07:34
Quantification of Circulating Pig-Specific DNA in the Blood of a Xenotransplantation Model
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Cited by 2 •
2020
In this protocol, porcine specific primers were designed, plasmids-containing porcine specific DNA fragments were constructed, and standard curves for quantitation were established. Using species-specific primers, cpsDNA was quantified by qPCR in pig-to-mouse cell transplantation models and pig-to-monkey artery patch transplantation models.
04:42
Isolation of Circulating Cell-free DNA (cfDNA): A Silica-based Membrane Procedure to Extract cfDNA from Blood Plasma of Cancer Patients
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2025
This video describes a silica-based membrane procedure to isolate circulating cell-free DNA or cfDNA from human plasma sample. The cfDNA is a promising biomarker for cancer diagnosis and...
FAQs
Apoptosis and necrosis contribute to release by allowing nucleosomal DNA fragments to enter plasma. These fragments are then transported and subject to clearance or degradation over time. Consequently, a measured circulating DNA signal reflects not only DNA release from cells but also how long fragments remain detectable, an important consideration when interpreting tissue or disease signals.
Analytical methods can examine sequence variation, methylation patterns, and fragment characteristics to distinguish tumor-derived circulating tumor DNA from normal cell-free DNA. These features provide different molecular signals associated with cellular or tissue origin. Using them helps researchers identify tumor-related material within the broader circulating DNA population rather than treating all detected fragments as equivalent.
Release and clearance shape how circulating DNA measurements should be interpreted because DNA enters plasma and is subsequently removed or degraded. A low or high signal may therefore reflect differences in cellular release, fragment persistence, or both. Ongoing research examines these processes to clarify how accurately circulating DNA represents tissue activity and other biological states.
A typical workflow isolates DNA fragments from plasma and then analyzes their sequence variation, methylation patterns, or fragment characteristics. The selected analysis depends on whether the goal is to identify tumor-derived material, recognize tissue-specific signals, or assess another biological context. These steps convert plasma DNA into molecular information that can support noninvasive investigation.
Circulating DNA supports liquid biopsy because plasma sampling can provide molecular information without directly sampling the tissue of interest. When tumor-derived circulating DNA is distinguished from normal cell-free DNA, the results can contribute to cancer monitoring. Sequence, methylation, and fragment analyses help characterize the tumor-related signal and follow cellular or tissue-associated changes.
Beyond oncology, circulating DNA analysis supports prenatal testing and transplant assessment by providing a noninvasive source of DNA-related information in body fluids. The broader value comes from examining sequence variation, methylation patterns, or fragment characteristics to identify biologically meaningful signals. These applications illustrate how plasma DNA can connect molecular measurements with tissue or cellular activity.