Separation and Washing of Candida Cells from White Blood Cells Using Viscoelastic Microfluidics

Area of Science:

• Biomedical Engineering
• Microfluidics
• Infectious Disease Diagnostics

Background:

• Candidemia, a bloodstream infection caused by Candida albicans, requires early diagnosis for effective antifungal treatment.
• Current diagnostic methods can be slow, delaying critical patient care.
• Improved sample preparation is essential for sensitive detection of low-pathogen loads.

Purpose of the Study:

• To develop and validate a microfluidic system for continuous separation, concentration, and washing of Candida cells from blood.
• To enhance the detectability of low-concentration Candida albicans in clinical samples.
• To facilitate rapid and accurate diagnosis of candidemia.

Main Methods:

• Utilized viscoelastic microfluidic techniques in a two-step system: a closed-loop separation/concentration device and a co-flow cell-washing device.
• Determined optimal flow conditions using particle mixtures to establish the flow rate factor.
• Applied the system to separate Candida cells from white blood cells (WBCs) and concentrate them.

Main Results:

• Achieved a 74.6-fold concentration of Candida cells from blood samples.
• Successfully separated Candida cells from WBCs and removed blood lysate.
• Enabled detection of extremely low Candida concentrations (initial Ct > 35) after processing (final Ct = 23.3 ± 1.6).

Conclusions:

• Viscoelastic microfluidics offers an efficient method for preparing blood samples for candidemia diagnosis.
• The developed system significantly enhances the sensitivity of Candida detection.
• This technology holds promise for improving early diagnosis and treatment of bloodstream fungal infections.