Abstract

Multiplexed Detection of Circulating Tumor DNA using Microfluidic Surface Plasmon Resonance (SPR) Sensormetry

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, detection of ctDNA in blood has been faced with conventional technical limits and called for innovative technologies and methods.
Here, we present a stable and selective assay for multiplexing detection of epidermal growth factor receptor (EGFR) mutation of most common mutations in plasma using DNA-DNA hybridization and selective linker prove with a lab-made surface plasmon resonance (SPR) sensometry. We prepared wild type and mutant templates of E746-A750 deletion in exon 19. Linker DNAs coated on a sensor surface of SPR capture different quantities of two different DNA types. Due to characteristics of SPR, the whole process was monitored in real-time and completed within an hour. Quantification data of SPR was compared with result of peptide nucleic acid (PNA) – locked nucleic acid (LNA) clamping PCR method for EGFR mutation detection. This study as a proof of concept can be further expanded into multiplexing detection of major and known ctDNAs, which could provide a solution for clinical unmet needs in cancer treatment and early detection.