Silicon-based microfilters for whole blood cell separation.

Area of Science:

• Biomedical Engineering
• Microfluidics
• Cell Separation Technologies

Background:

• Accurate isolation of white blood cells (WBCs) from whole blood is crucial for various diagnostic and research applications.
• Existing microfiltration methods face challenges in efficiency and integration for downstream processes.
• Silicon-based microfilters offer potential for precise cell manipulation due to their fabrication versatility.

Purpose of the Study:

• To compare the performance of four distinct silicon-based microfilter designs for separating white blood cells (WBCs) from red blood cells (RBCs).
• To evaluate key parameters including blood handling capacity, WBCs trapping efficiency, and RBCs passing efficiency.
• To identify the most effective microfilter design for potential integration into on-chip genomic analysis workflows.

Main Methods:

• Four silicon-based microfilter designs (weir, pillar, crossflow, and membrane) were fabricated with a consistent cut-off size of 3.5 µm.
• Human whole blood was utilized to characterize and compare the microfilters.
• Performance metrics evaluated included blood handling capacity, WBCs trapping efficiency, and RBCs passing efficiency.

Main Results:

• All tested microfilters were designed to selectively trap WBCs based on a 3.5 µm cut-off size.
• Comparative analysis revealed that the crossflow microfilter exhibited superior performance across the evaluated metrics.
• The crossflow design showed promising characteristics for integration with subsequent analytical steps.

Conclusions:

• The crossflow microfilter design is identified as the most effective among the four silicon-based microfilters evaluated for WBCs and RBCs separation.
• The superior performance of the crossflow microfilter suggests its suitability for integration into advanced on-chip systems, such as those for genomic analysis.
• This research provides valuable insights into the optimization of microfluidic devices for efficient cell separation in biomedical applications.