An inexpensive microfluidic device for three-dimensional hydrodynamic focusing in imaging flow cytometry

Area of Science:

• Biomedical Engineering
• Microfluidics
• Cellular Imaging

Background:

• Imaging flow cytometry requires precise cell manipulation for high-resolution analysis.
• Existing 3D hydrodynamic focusing devices often necessitate small dimensions and complex fabrication.
• There is a need for cost-effective and easily manufactured devices for advanced cell imaging.

Purpose of the Study:

• To design, characterize, and test an inexpensive microfluidic device for 3D hydrodynamic focusing.
• To enable single-file cell alignment near the microchannel bottom for high-magnification imaging.
• To provide guidelines for optimizing device parameters for various cell sizes.

Main Methods:

• Design and fabrication of a sheath-flow based microfluidic device with relatively large dimensions.
• 3D numerical simulations to characterize hydrodynamic focusing performance.
• Experimental validation using fluorescently dyed sample fluid and red blood cell imaging.

Main Results:

• The device achieves 3D hydrodynamic focusing of cells in a single file near the channel floor.
• Independent control over the focused stream's width and height is possible via channel dimensions and flow rates.
• Simulations provide guidelines for selecting device parameters for specific cell sizes.

Conclusions:

• The developed microfluidic device offers an inexpensive and easily fabricated solution for 3D cell focusing.
• Its design facilitates high-magnification imaging with standard objectives, applicable to various cell types and imaging modalities.
• This technology advances cell analysis in flow cytometry and microscopy.