(101b) Bioparticle Capture In a Sawtooth Dielectrophoretic Microchannel

Biological fluids can be considered to contain information-rich mixtures of biochemicals and particles that enable clinicians to accurately diagnose a wide range of pathologies.  Rapid and inexpensive analysis of blood and other bodily fluids is a topic gaining substantial attention in both science and medicine.  One line of development involves microfluidic approaches that provide unique advantages over entrenched technologies, including rapid analysis times, microliter sample and reagent volumes, potentially low cost and practical portability.  The present study focuses on the isolation and concentration of bioparticles using DC insulator-based gradient dielectrophoresis in a converging, sawtooth-patterned microchannel.  The channel design enables localized isolation and concentration of specific particles by exploiting variations in their characteristic physical properties.  Experiments have resulted in successful capture of human blood cells from small-volume samples of diluted whole blood.  The technique can operate with isotonic buffers, allowing capture of whole cells.  We have also demonstrated dielectrophoretic capture and concentration of mature amyloid protein fibrils.  In each case, reproducible capture occurred at specific locales within the sawtooth channel.