Multiple exosome RNA analysis methods for lung cancer diagnosis through integrated on-chip microfluidic system

Exosomes are now raising focus as a prospective biomarker for cancer diagnostics and prognosis owing to its unique bio-origin and composition. Exosomes take part in cellular communication and receptor mediation and transfer their cargos ( e.g. , proteins, mRNA and DNA). Quantitative analysis of tumor-related nucleic acid mutations can be a potential method to cancer diagnosis and prognosis in early stages. Here we present an integrated microfluidic system for exosome on-chip isolation and lung cancer RNA analysis through droplet digital PCR (ddPCR). Gradient dilution experiments show great linearity over a large concentration range with R 2 = 0.9998. Utilizing the system, four cell lines and two mutation targets were parallelly detected for mutation analysis. The experiments demonstrated mutation heterogeneity and the results were agree with cell researches. These results proved our integrated microfluidic system as a promising means for early cancer diagnosis and prognosis in the era of liquid biopsy. Integrated on-chip exosome isolation and RNA mutation analysis are accomplished through our system utilizing droplet digital PCR (ddPCR), in which four types of cell line exosomes and two mutation targets (EGFR L858R and KRAS) were parallelly detected for mutation analysis. The one-step exosome processing system is suitable for efficient, pollution-free, timely and non-invasive exosome detection.