A Continuous Flow-through Microfluidic Device for Electrical Lysis of Cells

Area of Science:

• Biomedical Engineering
• Electrical Engineering
• Cell Biology

Background:

• Traditional cell lysis methods often involve complex 3D electrode structures.
• There is a need for efficient, continuous, and scalable cell lysis techniques for biomedical applications.

Purpose of the Study:

• To propose and evaluate a simple flow-through microfluidic device for continuous and massive electrical cell lysis.
• To investigate the mechanism of cell lysis within the device and assess the role of electric fields and fluid dynamics.

Main Methods:

• Fabrication of a microchannel device with a planar electrode array on the bottom wall.
• Application of alternating current (AC) voltages to lyse cells in human whole blood.
• Calculation of electric field and Maxwell stress to analyze lysis mechanisms.
• Investigation of electro-thermally induced cross-flow for cell transport.

Main Results:

• Complete lysis of human whole blood cells was achieved within 7 seconds at a flow rate of 400 μL/hr using a 20 V peak-to-peak voltage at 1 MHz.
• Cell lysis primarily occurred in the lower half-channel where electric fields exceeded the irreversible electroporation threshold.
• Electro-thermally induced cross-flow was identified as crucial for transporting cells to the lysis zone.
• Calculated Maxwell shear stress was significantly lower than mechanical lysis thresholds, suggesting mechanical assistance could enhance lysis.

Conclusions:

• The developed flow-through device provides an efficient and scalable method for continuous electrical cell lysis.
• The lysis mechanism involves a combination of electrical stress and electro-thermally induced cross-flow.
• Further optimization by incorporating moderate mechanical stress may improve lysis efficiency.