文摘
In this work, we describe and implement an electrokineticapproach for single-nucleotide polymorphism (SNP) discrimination using a PDMS/glass-based microfluidic chip.The technique takes advantage of precise control of thecoupled thermal (Joule heating), shear (electroosmosis),and electrical (electrophoresis) energies present at anarray of probes afforded by the application of externalelectrical potentials. Temperature controllers and embedded thermal devices are not required. The chips can beeasily and inexpensively fabricated using standard microarray printing methods combined with soft-lithographypatterned PDMS fluidics, making these systems easilyadaptable to applications using higher density arrays.Extensive numerical simulations of the coupled flow andthermal properties and microscale thermometry experiments are described and used to characterize the in-channel conditions. It was found that optimal conditionsfor SNP detection occur at a lower temperature on-chipthan for typical microarray experiments, thereby revealingthe importance of the electrical and shear forces to theoverall process. To demonstrate the clinical utility of thetechnique, the detection of single-base pair mutations inthe survival motor neuron gene, associated with thechildhood disease spinal muscular atrophy, is conducted.