Shape-based separation of microalga Euglena gracilis using inertial microfluidics.

Area of Science:

• Biotechnology
• Microfluidics
• Algal research

Background:

• Euglena gracilis (E. gracilis) is a microalga with diverse applications in biodiesel and biomass production.
• Cell shape in E. gracilis is a critical biomarker reflecting physiological status and environmental conditions.
• Uniform E. gracilis populations are essential for consistent research outcomes and industrial processes.

Purpose of the Study:

• To develop a label-free, high-throughput, and continuous method for separating E. gracilis based on cell shape.
• To utilize microfluidic technology for precise sorting of E. gracilis by aspect ratio (AR).

Main Methods:

• A microfluidic device with a straight rectangular channel, expanding region, and multiple outlets was designed.
• Inertial microfluidics was employed to achieve cell focusing and ordering.
• Shape-activated differences in lateral inertial focusing positions were leveraged for separation.

Main Results:

• E. gracilis cells were successfully separated based on their aspect ratio (AR) ranging from 1 to 7.
• The microfluidic system demonstrated efficient sorting, directing cells with different ARs to distinct outlets.
• The technique is label-free, high-throughput, and continuous.

Conclusions:

• Inertial microfluidics provides an effective platform for shape-based separation of E. gracilis.
• This method enables the preparation of high-purity E. gracilis populations with uniform shapes.
• The developed technique has significant implications for advancing E. gracilis applications in biotechnology and research.