Standing Surface Acoustic Wave (SSAW)-Based Fluorescence-Activated Cell Sorter.

Area of Science:

• Biotechnology
• Microfluidics
• Acoustofluidics

Background:

• Microfluidic fluorescence-activated cell sorters (μFACS) offer inexpensive and biosafe cell identification and separation.
• Traditional FACS systems are often expensive and bulky.
• There is a need for high-performance, compact cell sorting technologies.

Purpose of the Study:

• To develop and characterize a high-performance μFACS integrated on a single chip.
• To utilize standing surface acoustic waves (SSAW) for cell focusing and deflection.
• To demonstrate efficient sorting of mammalian cells with high purity and throughput.

Main Methods:

• Integration of SSAW-based 3D cell-focusing, in-plane fluorescent detection, and SSAW-based cell-deflection units on a single microfluidic chip.
• Utilizing SSAW for sheath-flow-free, single-file cell focusing.
• Employing a focused interdigital transducer for acoustic cell deflection.
• Experimentally characterizing individual units and the integrated system.

Main Results:

• Demonstrated sheath-flow-free cell focusing into a single file using SSAW.
• Achieved accurate individual cell detection with an in-plane optical system.
• Obtained a sorting purity greater than 90% at a throughput of 2500 events s⁻¹ for HeLa cells.
• Validated the efficiency, speed, and biocompatibility of the SSAW-based FACS.

Conclusions:

• The integrated SSAW-based μFACS provides efficient, fast, and biosafe cell sorting.
• The device achieves high purity and throughput, comparable to traditional FACS.
• This technology presents a competitive, compact, and cost-effective alternative to conventional cell sorters.