Detection of tumor mutations in the presence of excess amounts of normal DNA

Xiyuan Sun, K. Hung, L. Wu, D. Sidransky, Baochuan Guo

Research output: Contribution to journalArticlepeer-review

44 Scopus citations


Mutations are important markers in the early detection of cancer. Clinical specimens such as bodily fluid samples often contain a small percentage of mutated cells in a large background of normal cells. Thus, assays to detect mutations leading to cancer need to be highly sensitive and specific. In addition, they should be possible to carry out in an automated and high-throughput manner to allow large-scale screening. Here we describe a screening method, termed PPEM (PNA-directed PCR, primer extension, MALDI-TOF), that addresses these needs more effectively than do existing methods. DNA samples are first amplified using peptide nucleic acid (PNA)-directed PCR clamping reactions in which mutated DNA is preferentially enriched. The PCR-amplified DNA fragments are then sequenced through primer extension to generate diagnostic products. Finally, mutations are identified using matrix-assisted laser-desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. This method can detect as few as 3 copies of mutant alleles in the presence of a 10, 000-fold excess of normal alleles in a robust and specific manner. In addition, the method can be adapted for simultaneous detection of multiple mutations and is amenable to high-throughput automation.

Original languageEnglish (US)
Pages (from-to)186-189
Number of pages4
JournalNature biotechnology
Issue number2
StatePublished - Feb 2002

ASJC Scopus subject areas

  • Biotechnology
  • Bioengineering
  • Applied Microbiology and Biotechnology
  • Molecular Medicine
  • Biomedical Engineering


Dive into the research topics of 'Detection of tumor mutations in the presence of excess amounts of normal DNA'. Together they form a unique fingerprint.

Cite this