Abstract

Multiple Detection of Circulating Tumor DNA on a Microfluidic Platform

Sehyun Shin, Professor & Director, Korea University

Circulating tumor DNA (ctDNA) has been demonstrated as the most promising biomarker for non-invasive assessment of cancer as well as the most accurate predictor of cancer treatment responses. However, there are several hundreds of tumor DNAs even for one organ cancer (i.e., Lung cancer) and thus multiplexing is highly required for cancer detection from blood. The conventional techniques have been faced critical limits including multiplexing and cost and innovative technologies are highly required. Here, we present a stable and selective assay for detecting epidermal growth factor receptor (EGFR) mutations in plasma (or liquid biopsy) using DNA-DNA hybridization and Au nanoparticle probe with a lab-made surface plasmon resonance (SPR) sensometry. Target DNAs are amplified in a closed-loop microfluidic PCR module consisting of three different temperature regions. We prepared wild type EGFR, EGFR mutants including point mutation and deletion. Linker DNAs coated on a sensor surface of SPR captured different DNA types. Due to characteristics of SPRi, the whole assay process was monitored in real-time and completed within an hour. This study as a proof of concept can be further expanded into high degree of multiplexing detection of major and known ctDNAs, which could provide a solution for clinical unmet needs in cancer treatment and early detection.