On-chip immuno-agglutination assay with analyte capture by dynamic manipulation of superparamagnetic beads.
Magnetic bead-based lab-on-a-chip systems offer significant advantages compared to more conventional systems, mainly through the possibility of controlled manipulation of the magnetic carriers on-chip. In particular, microfluidic immunoassays using functionalized magnetic beads raise increasing interest. We present here a new approach for performing immuno-agglutination assays on-chip. Our system is based on a quadrupolar magnetic field set-up. Dynamic actuation of a confined plug of functionalized magnetic beads is used for analyte capture in a microchannel. A simple detection method based on the swelling of the released plug after agglutination is presented. We demonstrate the feasibility of on-chip agglutination tests by means of a streptavidin/biotinylated-bovine serum albumin (bBSA) model assay. A detection limit of about 200 pg/mL (approximately 3 pM) is achieved.
Laboratory of Microsystems, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland. yves.moser@epfl.ch
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Lehnert
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D000372:Agglutination Tests / Q000379:methods*; D000818:Animals; D001681:Biological Assay / Q000379:methods*; D002417:Cattle; D018189:Immunomagnetic Separation / Q000379:methods*; D008280:Magnetics; D046210:Microfluidic Analytical Techniques / Q000379:methods*; D008954:Models, Biological; D012710:Serum Albumin, Bovine; D019809:Streptavidin / Q000737:chemistry
D012710:Serum Albumin, Bovine; D019809:Streptavidin