Related Experiment Video
Updated: Aug 20, 2026
Detection of Cell-Free DNA in Blood Plasma Samples of Cancer Patients
Published on: September 9, 2020
[Quantitative analysis of circulating DNA in serum of cancer patients]
Hong Tu1, Hai-feng Gao, Shi-long Fu
1Shanghai Cancer Institute/Cancer Institute of Shanghai Jiao-Tong University, Shanghai 200032, China. tuhong66@yahoo.com
Objective:
To develop a method for ng quantitation of circulating DNA in serum and explore the value in the diagnosis of cancer.
Methods:
Serum DNA was extracted by commercial "genomic DNA extraction kit" and detected by fluorescent dye (SYBR green I) staining. Loss of heterozygosity (LOH) at BRCA1 (D17S579, D17S855) and p53 (TP53, D17S786) in serum DNA was analyzed by PCR-based method.
Results:
SYBR green I dot staining could detect DNA as low as 2 ng. Using this method, we detected serum samples from 483 patients with various types of cancer and 150 healthy individuals. The mean DNA concentration in the normal controls was 22.2 +/- 13.4 ng/ml, while that in cancer patients was 81.3 +/- 98.3 ng/ml (P < 0.001). In 33 ovarian cancer patients with increased DNA level, 27(81.8%) displayed LOH in at least one of the four loci analyzed.
Conclusion:
Circulating DNA in serum may become additional tumor marker for the diagnosis of cancer.
