A portable impedance microflow cytometer for measuring cellular response to hypoxia

Area of Science:

• Biomedical Engineering
• Cellular Biology
• Medical Diagnostics

Background:

• Sickle cell disease (SCD) diagnosis and monitoring often require specialized laboratory equipment.
• Portable and low-cost diagnostic tools are needed for field and low-resource settings.
• Understanding cellular responses to microenvironmental changes, like oxygen levels, is crucial for disease characterization.

Purpose of the Study:

• To develop and validate a low-cost, portable electrical impedance-based microflow cytometer for single-cell analysis.
• To assess the system's capability in differentiating sickle cell disease blood samples from normal samples.
• To investigate cellular electrical property changes in response to controlled oxygen microenvironments.

Main Methods:

• Development of a microflow cytometer integrating an impedance analyzer chip, microfluidic chip, and microcontroller.
• Utilizing a custom Android application for system operation and data acquisition.
• Conducting case studies on human red blood cells (RBCs) from normal and sickle cell disease patients under varying oxygen conditions.

Main Results:

• The microflow cytometer successfully identified distinct impedance patterns for sickle cell disease blood samples compared to normal samples.
• A conformity score effectively quantified intrapatient and interpatient variations in SCD.
• Hypoxia treatment induced significant changes in RBC cytoplasmic resistance and membrane capacitance, with SCD cells showing a more pronounced response.

Conclusions:

• The developed low-cost microflow cytometer demonstrates potential as a screening technique for sickle cell disease in resource-limited settings.
• The system can differentiate between normal and sickle cell blood based on impedance measurements under varying oxygen levels.
• The methodology offers a platform for analyzing cellular responses to hypoxia in various cell types.