dCas9-Mediated PCR-Free Detection of Oncogenic Mutation by Nonequilibrium Nanoelectrokinetic Selective Preconcentration.

Cutting-edge nanoelectrokinetic technology in this work provides a breakthrough for the present clinical demands of molecular diagnosis to detect a trace amount of oncogenic mutation of DNA in a short time without an erroneous PCR procedure. In this work, we combined the sequence-specific labeling scheme of CRISPR/dCas9 and ion concentration polarization (ICP) mechanism to separately preconcentrate target DNA molecules for rapid detection. Using the mobility shift caused by dCas9's specific binding to the mutant, the mutated DNA and normal DNA were distinguished in the microchip. Based on this technique, we successfully demonstrated the dCas9-mediated 1-min detection of single base substitution (SBS) in EGFR DNA, a carcinogenesis indicator. Moreover, the presence/absence of target DNA was identified at a glance like a commercial pregnancy test kit (two lines for positive and one line for negative) by the distinct preconcentration mechanisms of ICP, even at the 0.1% concentration of the target mutant.