Multinode acoustic focusing for parallel flow cytometry.

Flow cytometry can simultaneously measure and analyze multiple properties of single cells or particles with high sensitivity and precision. Yet, conventional flow cytometers have fundamental limitations with regards to analyzing particles larger than about 70 μm, analyzing at flow rates greater than a few hundred microliters per minute, and providing analysis rates greater than 50,000 per second. To overcome these limits, we have developed multinode acoustic focusing flow cells that can position particles (as small as a red blood cell and as large as 107 μm in diameter) into as many as 37 parallel flow streams.

Particle focusing in staged inertial microfluidic devices for flow cytometry.

Microfluidic inertial focusing has been demonstrated to be an effective method for passively positioning microparticles and cells without the assistance of sheath fluid. Because inertial focusing produces well-defined lateral equilibrium particle positions in addition to highly regulated interparticle spacing, its value in flow cytometry has been suggested. Particle focusing occurs in straight channels and can be manipulated through cross sectional channel geometry by the introduction of curvature.

Particle size limits when using optical trapping and deflection of particles for sorting using diode laser bars.

We explore a simple, inexpensive approach to large particle manipulation using diode laser bar optical trapping. This method overcomes limitations that prevent conventional point laser traps from effectively directing large particles. Expanding a previously developed line optical trap model into larger particle regimes, we verify and examine the advantages and limitations of diode laser bar trapping for manipulating particles greater than 100 microm in diameter within fluidic environments for biochemical, biological, and biomedical applications.

Microfluidic sorting system based on optical waveguide integration and diode laser bar trapping.

Effective methods for manipulating, isolating and sorting cells and particles are essential for the development of microfluidic-based life science research and diagnostic platforms. We demonstrate an integrated optical platform for cell and particle sorting in microfluidic structures. Fluorescent-dyed particles are excited using an integrated optical waveguide network within micro-channels.