Picoliter nDEP traps enable time-resolved contactless single bacterial cell analysis in controlled microenvironments

Area of Science:

• Microfluidics
• Cell Biology
• Biotechnology

Background:

• Traditional methods struggle with precise control over individual cell environments.
• Culturing single cells requires isolation from external influences like surfaces and other cells.

Purpose of the Study:

• To develop a novel lab-on-a-chip device for contactless, single bacterial cell cultivation.
• To enable precise control over the microenvironment of individual bacterial cells.
• To investigate single-cell growth dynamics under controlled conditions.

Main Methods:

• Utilized negative dielectrophoresis (nDEP) with miniaturized octupole electrodes for cell trapping.
• Developed a novel bonding technology for biocompatible 3D electrode fabrication.
• Employed computer-aided flow simulations for microfluidic isolation and perfusion.
• Integrated nDEP cell sorting with time-resolved contactless cultivation in a picoliter bioreactor.

Main Results:

• Achieved stable, contactless trapping and cultivation of single bacterial cells (e.g., Bacillus subtilis, E. coli).
• Demonstrated reduced Joule heating due to miniaturized electrode geometries.
• Observed significantly faster and consistent growth rates compared to population-level cultures.
• Showcased cell-type independent trapping capabilities.

Conclusions:

• The Envirostat 2.0 provides unprecedented microenvironmental control for single bacterial cells.
• This technology facilitates accurate analysis of bacteria and small eukaryotes, free from surface and cell-cell interactions.
• Offers significant potential for advancing microfluidic-based cell analysis and synthetic biology.