Circulating Cell-free Dna
Circulating Cell-free Dna - Related Videos
08:29
Profiling Epidermal Growth Factor Receptor DNA Mutations in Circulating Rare Cells Using a Cell Isolation System and Droplet Digital PCR
0 Views •
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.
04:42
Isolation of Circulating Cell-free DNA (cfDNA): A Silica-based Membrane Procedure to Extract cfDNA from Blood Plasma of Cancer Patients
0 Views •
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...
06:53
Detection and Monitoring of Tumor Associated Circulating DNA in Patient Biofluids
0 Views •
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.
05:22
Isolation and Propagation of Circulating Tumor Cells from a Mouse Cancer Model
0 Views •
Cited by 8 •
2015
Circulating tumor cells (CTCs) have been shown to play an important role in tumor metastasis. Here, a method for the isolation and propagation of CTCs from the whole blood of a syngeneic mouse tumor model of hepatocellular carcinoma (HCC) metastasis is described.
07:37
Circulating MicroRNA Quantification Using DNA-binding Dye Chemistry and Droplet Digital PCR
0 Views •
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.
FAQs
Circulating cell-free DNA reaches plasma through apoptosis, necrosis, and active secretion, which represent different cellular routes for releasing DNA. Apoptosis and necrosis reflect cellular turnover or injury, whereas active secretion provides a regulated route. These routes connect the measured DNA pool to normal physiology, tissue damage, or disease and help explain why its biochemical composition can vary between biological states.
Nucleases fragment genomic DNA after it enters circulation, while the liver and kidneys contribute to rapid removal. Consequently, a plasma measurement reflects a balance between release, fragmentation, and clearance rather than the amount released by cells alone. This balance matters when interpreting cfDNA as a biochemical indicator, because organ processing can influence how much tissue-associated DNA remains available for analysis.
Genetic variants provide sequence-level clues, whereas tissue-specific methylation patterns provide biochemical information about the tissue associated with the DNA. These readouts can also be examined in relation to fetal DNA found in maternal plasma. Together, they connect circulating molecules with tissue identity, disease-related changes, or physiological state and expand analysis beyond simply detecting DNA outside cells.
DNA found in maternal plasma can include fetal DNA, making biochemical analysis of that plasma a source of fetal genetic information without directly sampling fetal tissue. The relevant signal is therefore obtained from a maternal blood-based sample and interpreted through DNA analysis. This application demonstrates how cfDNA can provide prenatal information within maternal circulation.
In cancer liquid biopsies, analysts can examine cfDNA for genetic variants released into blood. These variants may provide biochemical evidence associated with cancer-related cellular changes, allowing blood plasma to serve as the analyzed material rather than requiring direct access to the tissue in the context described. The approach supports study of disease-associated molecular signals through a circulating sample.
Transplant monitoring and disease-injury studies use cfDNA measurements because the circulating pool provides information related to cellular damage and tissue-specific biochemical signals. Genetic variants or methylation patterns can supply molecular information, while release and clearance processes provide context for interpreting it. This makes cfDNA useful for following tissue-associated changes without treating plasma DNA as a direct measure of damage alone.