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Updated: Jul 14, 2025
Detection and Monitoring of Tumor Associated Circulating DNA in Patient Biofluids
Published on: June 8, 2019
Fast, sensitive, and specific multiplexed single-molecule detection of circulating tumor DNA
Soochul Shin1, Sun Han1, Juyoung Kim1
1Department of Physics and Astronomy, Institute of Applied Physics, Seoul National University, Seoul, Republic of Korea.
Abstract:
Circulating tumor DNA (ctDNA) analysis has emerged as a highly promising non-invasive assay for detection and monitoring of cancer. However, identification of multiple point-mutant ctDNAs, particularly at extremely low frequencies in early cancer stages, remains a significant challenge. To address this issue, we present a multiplexed ctDNA detection technique, SIMUL (single-molecule detection of multiple low-frequency mutations). SIMUL involves an unbiased preamplification of both wild-type and mutant DNAs, followed by the detection of mutant DNAs through single-molecule multicolor imaging. SIMUL enables highly sensitive and specific detection of multiple single-nucleotide mutations in a short span of time, even in the presence of 10,000-fold excess of wild-type DNA. Importantly, SIMUL can accurately measure mutant fractions due to its linear correlation between the number of single-molecule spots and the variant allele frequency. This breakthrough technique holds immense potential for clinical applications, offering significant improvements for example in early cancer detection and accurate evaluation of anticancer treatment responses.
Insights
A new method called SIMUL (single-molecule detection of multiple low-frequency mutations) can detect multiple cancer DNA mutations at low levels. This non-invasive technique improves early cancer detection and treatment monitoring.
Area of Science:
- Molecular Biology
- Genomics
- Biotechnology
Background:
- Circulating tumor DNA (ctDNA) analysis is a promising non-invasive method for cancer detection and monitoring.
- Identifying multiple low-frequency point-mutant ctDNAs, especially in early cancer stages, presents a significant challenge.
Purpose of the Study:
- To develop a multiplexed ctDNA detection technique for sensitive identification of multiple low-frequency mutations.
- To overcome the limitations of current methods in detecting low-abundance mutant ctDNAs.
Main Methods:
- Developed SIMUL (single-molecule detection of multiple low-frequency mutations), a multiplexed ctDNA detection technique.
- Employed unbiased preamplification of wild-type and mutant DNAs.
- Utilized single-molecule multicolor imaging for mutant DNA detection.
Main Results:
- SIMUL achieves highly sensitive and specific detection of multiple single-nucleotide mutations.
- The method is effective even with a 10,000-fold excess of wild-type DNA.
- Accurate measurement of mutant fractions is possible due to a linear correlation between single-molecule spots and variant allele frequency.
Conclusions:
- SIMUL is a breakthrough technique for sensitive and specific detection of multiple low-frequency ctDNA mutations.
- The method offers significant potential for clinical applications, including early cancer detection and response evaluation to anticancer treatments.
- SIMUL enhances the capabilities of non-invasive cancer diagnostics.
