Continuous organelle separation in an insulator-based dielectrophoretic device.

Area of Science:

• Biophysics
• Cell Biology
• Microfluidics

Background:

• Organelle size heterogeneity is linked to diseases like neurodegenerative disorders and cancer.
• Understanding organelle subpopulations is vital for elucidating disease mechanisms.
• Current methods for organelle separation require improvement for detailed biomolecular analysis.

Purpose of the Study:

• To develop a microfluidic device for size-based separation of submicrometer particles, including organelles.
• To investigate a novel ratchet migration mechanism for enhanced particle separation.
• To enable the collection of fractionated organelles for future biomolecular studies.

Main Methods:

• Utilized insulator-based dielectrophoresis with a continuous flow system.
• Designed a microfluidic device with an array of insulating posts to control electrokinetic and dielectrophoretic transport.
• Developed a numerical model to simulate particle migration and size-based separation.
• Experimentally validated the device using polystyrene beads and isolated mitochondria.

Main Results:

• Achieved size-based separation of polystyrene beads (0.28 and 0.87 $$ m) with good agreement to numerical simulations.
• Demonstrated distinct size-related migration behavior in mitochondria from HepG2 cells and Mfn-1 knockout HepG2 cells.
• The ratchet migration mechanism effectively separated particles based on size.

Conclusions:

• The developed microfluidic device offers a promising approach for size-based organelle separation.
• This technology facilitates the study of organelle subpopulations differing in size.
• Enables future access to the biomolecular signatures of distinct organelle populations for disease research.