An electrostatic microwell-based biochip for phytoplanktonic cell trapping

Area of Science:

• Biotechnology
• Microfluidics
• Cell Biology

Background:

• Microalgal cell manipulation is crucial for research and industrial applications.
• Existing methods for cell trapping can be inefficient or lack control over experimental conditions.

Purpose of the Study:

• To develop a simple microwell-based microfluidic chip for effective microalgal cell trapping.
• To investigate the use of an electrostatic trapping mechanism for diverse microalgal species.
• To assess the impact of trapping on cell viability and enable controlled micro-environments for experiments.

Main Methods:

• Fabrication of a microwell-based microfluidic chip.
• Implementation of an electrostatic cell trapping mechanism utilizing a positively charged glass surface.
• Testing the chip's capacity to capture various microalgal cell types, including filamentous Spirulina platensis.
• Assessing filament size distribution and cell growth post-trapping.
• Demonstrating liquid replacement for controlled chemical conditions and cell transfer for strain selection.

Main Results:

• The chip successfully captured multiple microalgal cell types.
• Single filament occupancy of up to ~30% of available wells was achieved for Spirulina platensis.
• No preferential size was observed for captured filaments, indicating random trapping.
• Electrostatic attraction did not negatively impact cell growth.
• Complete liquid replacement and subsequent cell transfer for strain selection were demonstrated.

Conclusions:

• The developed microfluidic chip provides an efficient and simple method for microalgal cell trapping.
• The electrostatic trapping mechanism is effective for various microalgal species and does not impede cell growth.
• The chip's design supports controlled micro-environmental experiments and serves as a platform for strain selection.