Hydrodynamic flow cytometer performance enhancement by two-dimensional acoustic focusing.

Area of Science:

• Biomedical Engineering
• Acoustic Technology
• Cellular Analysis

Background:

• Conventional flow cytometers use hydrodynamic focusing, which can reduce precision at high flow velocities.
• Cellular deviation and clogging are significant limitations in current flow cytometry techniques.

Purpose of the Study:

• To develop and validate a two-dimension ultrasonic particle focusing method for enhancing flow cytometer performance.
• To overcome the precision limitations of hydrodynamic focusing in flow cytometry.

Main Methods:

• Utilized two piezoelectric transducers on a fused silica flow channel for ultrasonic focusing.
• Employed finite element model simulation for parameter analysis and experimental design.
• Tested focusing effects using 3 μm polystyrene fluorescent particles and Jurkat cells.

Main Results:

• Achieved one-dimension acoustic focusing at 2.95 MHz (single node) and multiple nodes near 6, 9, and 12 MHz.
• Demonstrated a two-dimensional focused particle stream width under 10 μm.
• Verified applicability for Jurkat cells, maintaining stable flow without clogging at high concentrations and velocities over 100 μl/min.

Conclusions:

• The two-dimension ultrasonic particle focusing method significantly enhances flow cytometer performance.
• This acoustic approach offers a viable solution for improving detection accuracy and sample throughput.
• Minor modifications integrating ultrasonic transducers can upgrade existing hydrodynamic flow cytometers.