Dielectrophoretic Microfluidic Designs for Precision Cell Enrichments and Highly Viable Label-Free Bacteria Recovery...

Area of Science:

• Biomedical Engineering
• Microfluidics
• Cellular Biology

Background:

• Cellular analysis of biological samples faces challenges in cell sorting and recovery.
• Label-free microfluidics offer a promising solution for complex sample processing.
• Escherichia coli (E. coli) infections are a significant global health concern.

Purpose of the Study:

• To investigate label-free microfluidic device designs for enriching E. coli from whole human blood.
• To evaluate device performance in terms of throughput, scalability, precision, and recovery viability.
• To mimic infection workflows for early pathogen detection.

Main Methods:

• Utilized dielectrophoresis (DEP) for particle manipulation and cell sorting.
• Compared two microfluidic designs: CytoChip D (continuous flow) and CytoChip B (batch or continuous).
• Assessed recovery rates and purity of E. coli from spiked whole human blood samples.

Main Results:

• CytoChip D showed potential for high throughput but failed in effective bacteria recovery.
• CytoChip B achieved over 98% purity recovery of E. coli, even at ultra-low concentrations (<100 CFU/mL).
• Demonstrated feasibility for processing and recovering low bacterial concentrations for downstream applications.

Conclusions:

• CytoChip B is a viable technology for high-purity recovery of E. coli from blood.
• This method supports downstream analysis, bacterial culture, and drug testing for infection diagnostics.
• Future work will focus on scaling CytoChip B for increased sample volume processing.