Latex immunoagglutination assay for a vasculitis marker in a microfluidic device using static light scattering...

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Immunodiagnostics

Background:

• Current immunoassay methods often require complex equipment or labels.
• There is a need for portable, cost-effective diagnostic tools for point-of-care applications.

Purpose of the Study:

• To develop a microfluidic immunoassay device utilizing fiber optics and static light scattering (SLS).
• To demonstrate the device's capability for detecting specific biomarkers, such as vasculitis markers.

Main Methods:

• Fabrication of a microfluidic device integrated with fiber optics for light delivery and collection.
• Utilizing a miniature spectrometer to measure forward light scattering from latex microsphere agglutination.
• Employing anti-mouse IgG and anti-PR3 as target analytes with corresponding antibody-coated microspheres.

Main Results:

• Successful detection of anti-mouse IgG and the vasculitis marker anti-PR3 without false positives or negatives.
• Achieved a limit of detection (LOD) of 50 ng/mL for anti-PR3.
• Demonstrated detection using plasma samples from patients with vasculitis, showing a median anti-PR3 level of 380 ng/mL.

Conclusions:

• The developed fiber optic-based microfluidic immunoassay is a sensitive and specific detection method.
• The system is cost-effective, portable, and re-usable, paving the way for point-of-care diagnostics.
• This label-free optical detection approach offers a promising alternative to traditional immunoassay techniques.