Dielectrophoresis and shear-enhanced sensitivity and selectivity of DNA hybridization for the rapid discrimination of Candida species.
We present a dielectrophoresis (DEP)-based microfluidic chip that is capable of enhancing the sensitivity and selectivity of DNA hybridization using an AC electric field and hydrodynamic shear in a continuous through-flow. Molecular DEP was employed to rapidly trap ssDNA molecules in a flowing solution to a cusp-shaped nanocolloid assembly on a microfluidic chip with a locally amplified AC electric field gradient. The detection time can be accelerated to sub-minute periods, and the sensitivity can reach the pico-molar level due to the AC DEP-enhanced molecule concentration (at an optimal AC frequency of 900 kHz) in a small region (∼100 μm(2)) instead of the broad area used in a tank reactor (∼10(6) μm(2)). Continuous flow in a microchannel provides a constant and high shear rate that can shear off most non-specific target-probe binding to promote the discriminating selectivity. On-chip multi-target discrimination of Candida species can be achieved within a few minutes under optimal conditions.
Department of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan, ROC.
I-Fang
IF
Cheng
Huan-Wen
HW
Han
Hsien-Chang
HC
Chang
D002175:Candida / Q000235:genetics / Q000302:isolation & purification*; D004247:DNA / Q000235:genetics*; D046210:Microfluidic Analytical Techniques / Q000379:methods*; D009693:Nucleic Acid Hybridization / Q000379:methods*; D016133:Polymerase Chain Reaction; D012680:Sensitivity and Specificity
D004247:DNA