Quantification of Fewer than Ten Copies of a DNA Biomarker without Amplification or Labeling
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- 作者：Yoonhee Lee ; Youngkyu Kim ; Donggyu Lee ; Dhruvajyoti Roy ; Joon Won Park
- 刊名：Journal of the American Chemical Society
- 出版年：2016
- 出版时间：June 8, 2016
- 年：2016
- 卷：138
- 期：22
- 页码：7075-7081
- 全文大小：428K
- 年卷期：0
- ISSN：1520-5126
文摘
Polymerase chain reaction (PCR) is a highly sensitive diagnosis technique for detection of nucleic acids and for monitoring residual disease; however, PCR can be unreliable for samples containing very few target molecules. Here, we describe a quantification method, using force–distance (FD) curve based atomic force microscopy (AFM) to detect a target DNA bound to small (1.4–1.9 μm diameter) probe DNA spots, allowing mapping of entire spots to nanometer resolution. Using a synthetic BCR-ABL fusion gene sequence target, we examined samples containing between one and 10 target copies. A high degree of correlation (r2 = 0.994) between numbers of target copies and detected probe clusters was observed, and the approach could detect the BCR-ABL biomarker when only a single copy was present, although multiple screens were required. Our results clearly demonstrate that FD curve-based imaging is suitable for quantitative analysis of fewer than 10 copies of DNA biomarkers without amplification, modification, or labeling.