Guha, MinakshiCastellanos-Rizaldos, ElenaLiu, PingfangMamon, HarveyMakrigiorgos, Gerassimos2013-10-172012Guha, Minakshi, Elena Castellanos-Rizaldos, Pingfang Liu, Harvey Mamon, and G. Mike Makrigiorgos. 2012. Differential strand separation at critical temperature: a minimally disruptive enrichment method for low-abundance unknown DNA mutations. Nucleic Acids Research 41(3): e50.0305-1048http://nrs.harvard.edu/urn-3:HUL.InstRepos:11180395Detection of low-level DNA variations in the presence of wild-type DNA is important in several fields of medicine, including cancer, prenatal diagnosis and infectious diseases. PCR-based methods to enrich mutations during amplification have limited multiplexing capability, are mostly restricted to known mutations and are prone to polymerase or mis-priming errors. Here, we present Differential Strand Separation at Critical Temperature (DISSECT), a method that enriches unknown mutations of targeted DNA sequences purely based on thermal denaturation of DNA heteroduplexes without the need for enzymatic reactions. Target DNA is pre-amplified in a multiplex reaction and hybridized onto complementary probes immobilized on magnetic beads that correspond to wild-type DNA sequences. Presence of any mutation on the target DNA forms heteroduplexes that are subsequently denatured from the beads at a critical temperature and selectively separated from wild-type DNA. We demonstrate multiplexed enrichment by 100- to 400-fold for KRAS and TP53 mutations at multiple positions of the targeted sequence using two to four successive cycles of DISSECT. Cancer and plasma-circulating DNA samples containing traces of mutations undergo mutation enrichment allowing detection via Sanger sequencing or high-resolution melting. The simplicity, scalability and reliability of DISSECT make it a powerful method for mutation enrichment that integrates well with existing downstream detection methods.en-USJournal Article2013-10-1710.1093/nar/gks1250