An On-Chip Pcr Approach Enabling Cancer Diagnosis

Abstract

The development of microfluidic platforms broke the barrier for rampant growth of on-chip biomarker identification in the field of disease diagnostics. Unfortunately, the amplification of nucleic acids directly from raw patient blood has yet to find a simple but complete design on a point-of-care microfluidic device. Here we report a technological approach to detect circulating DNA typically found in whole blood of cancer patients through an on-chip blood-plasma separation, filtration, reagent mixing, and PCR amplification. Raw patient sample blood will first be placed through a self-driven, gravitational and drag powered filtration system, where separation times as low as 10 minutes per 5 μL of blood can be achieved. Plasma separation coupled with nitrocellulose filters will lead to a 99% pure plasma product. Patient plasma can then be properly placed into micro-chambers, where they will be exposed to corresponding lyophilized reagents and enzymes. With each well equipped to an individual micro-heater, concentrated thermo-cycling induces DNA amplification by following golden-standard PCR methodology on a minute-scale basis. Amplification of nucleic acids in the steps indicated above present a simple device design for diagnosis of DNA biomarkers from patient to PCR. To thoroughly accomplish all desired tasks in a direct and efficient manner, the components of an on-chip PCR platform will include a simple yet powerful blood separation method, lyophilized reagent storage, and micro-heated thermo-cycling.