Particle focusing in staged inertial microfluidic devices for flow cytometry

Area of Science:

• Biomedical Engineering
• Microfluidics
• Analytical Chemistry

Background:

• Microfluidic inertial focusing offers passive particle and cell positioning without sheath fluid.
• It establishes defined lateral equilibrium positions and regulated interparticle spacing, valuable for flow cytometry.
• Channel geometry, including curvature, can manipulate particle focusing.

Purpose of the Study:

• To present a staged microfluidic channel design combining straight and curved sections for particle ordering.
• To evaluate the performance of these staged inertial focusing channels using flow cytometry methods.
• To determine measurement precision and resolution as functions of flow velocity and particle concentration.

Main Methods:

• Utilized a staged microfluidic channel design with straight and curved sections.
• Employed standard flow cytometry techniques with calibration microspheres for performance evaluation.
• Analyzed measurement precision and resolution based on flow velocity and particle concentration.

Main Results:

• Staged inertial focusing channels effectively order particles into a single streamline with longitudinal spacing.
• Channel performance improved with higher flow rates and particle concentrations, suitable for high-throughput analysis.
• The prototype flow cytometer demonstrated resolution comparable to commercial systems and virtually eliminated particle coincidence.

Conclusions:

• Staged inertial focusing microchannels offer a promising approach for flow cytometry.
• These channels enhance throughput, precision, and resolution while minimizing particle coincidence.
• The technology has potential for developing cost-effective flow cytometry diagnostics and analyzing high particle concentrations.