An On-Chip Bifurcated Continuous Field-Flow Fractionation (BCFFF) Technology for Nucleic Acid Isolation.
Student: James Lutaaya, 2021-2022
Sponsor: BCFFF Medical Diagnostic Technology, University of Notre Dame, South Bend, Indiana.
We have designed and validated an on-chip field-flow nucleic acid extraction BCFFF technology by using an ionic transistor to achieve local ionic strength control. This is done in a way that the target molecules in a continuous flow main channel can be extracted with a high field at a junction with a bifurcated channel. The high field of the bifurcated- channel design, coupled with hydrodynamic drag, allows effective removal of both high-mobility counterion and low- mobility protein inhibitors. The BCFFF platform is versatile and can be applied for isolation of both long dsDNAs and short miRNAs, without changing the device configuration or the operation protocol. High-efficiency (>85%) concentration-independent DNA extraction and 40% net rtPCR miRNA yield from plasma are reported, which is significantly higher than any other commercial liquid and solid extraction technologies. This chip-based extraction technology can be integrated with upstream lysis and downstream on-chip qRT-PCR module to build a fully integrated nucleic acid analysis platform with high throughput, sensitivity and quantification accuracy. Rapid and absolute quantification of nucleic acids in plasma is hence enabled with a minimum of steps.