Latex immunoagglutination assay for a vasculitis marker in a microfluidic device using static light scattering detection.
We have developed a microfluidic immunoassay device using fiber optics to detect static light scattering (SLS) of latex microsphere agglutination. A 400-mum silica fiber was used to deliver blue light emitting diode (LED) or red laser light sources. A miniature, portable spectrometer was used to measure forward light scattering intensity collected by the same type of multi-mode fiber. To first show feasibility, anti-mouse IgG were used as target biomolecules and highly carboxylated polystyrene latex microspheres (510 nm) coated with mouse IgG were used as probes. Next, we tested for the vasculitis marker, anti-PR3, using the same type of microspheres coated with PR3 proteins. No false negatives or positives were observed. A limit of detection (LOD) of 50 ng mL(-1) was demonstrated for the vasculitis marker, anti-PR3. (Plasma samples from patients with vasculitis exhibited anti-PR3 at a median level of 380 ng mL(-1).) The optical detection system works without any fluorescence or chemiluminescence markers. The entire system proposed here is cost effective, small in size, and re-usable with simple rinsing. This may eventually lead to a portable, low-cost, re-useable, microfluidic, point of care immunoassay device.
Lucas
Lonnie J
LJ
Department of Agricultural and Biosystems Engineering, The University of Arizona, Tucson, AZ 85721-0038, USA.
Han
Jin-Hee
JH
Chesler
Jennine
J
Yoon
Jeong-Yeol
JY
D000906:Antibodies / Q000032:analysis*; D015415:Biomarkers / Q000378:metabolism*; D005336:Fiber Optic Technology; D007118:Immunoassay; D007841:Latex Fixation Tests; D008027:Light; D046210:Microfluidic Analytical Techniques; D053146:Myeloblastin / Q000276:immunology; D055100:Optical Fibers; D012542:Scattering, Radiation; D014657:Vasculitis / Q000175:diagnosis* / Q000276:immunology / Q000378:metabolism
D000906:Antibodies; D015415:Biomarkers; D053146:Myeloblastin