title: Rapid protein depletion from complex samples using a bead-based microfluidic device for the point of care.
abstract: Translation of sample preparation methods to point-of-care formats has remained a challenge. We present a plastic laminate microfluidic device for protein depletion from human plasma using ligand immobilized porous beads stored dry within a novel, pneumatically-driven mixer. The card design accelerated the protein depletion process from hours to minutes. Using immunoglobulin G as a model protein, we have successfully shown protein removal efficiency from spiked buffer between 70-80% and from diluted human plasma samples between 66-77%. Low non-specific binding of our downstream target ligand, immunoglobulin M, was observed with the spiked buffer and diluted human plasma samples. For future device optimization, the physical limitations to rapid protein removal on card were also explored. Bench-top experiments with improved mixing efficiency and a lower sample dilution factor achieved 99% IgG removal using the same amount of mixing time. This design can easily be adapted for depletion of other high abundance or interfering proteins by inclusion of other ligand immobilized beads.
authors.affiliation: Department of Bioengineering, University of Washington, Box 355061, Foege N530J, Seattle, WA 98195-5061, USA. kmckenz@u.washington.edu
authors.forename: Katherine G
authors.initials: KG
authors.lastname: McKenzie
authors.forename: Lisa K
authors.initials: LK
authors.lastname: Lafleur
authors.forename: Barry R
authors.initials: BR
authors.lastname: Lutz
authors.forename: Paul
authors.initials: P
authors.lastname: Yager
mesh_terms: D000327:Adsorption; D053000:Analytic Sample Preparation Methods / Q000191:economics / Q000295:instrumentation* / Q000379:methods; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D055767:Immobilized Proteins / Q000737:chemistry / Q000378:metabolism; D007074:Immunoglobulin G / Q000032:analysis / Q000097:blood* / Q000302:isolation & purification* / Q000378:metabolism; D046210:Microfluidic Analytical Techniques; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000378:metabolism; D010969:Plastics / Q000737:chemistry; D019095:Point-of-Care Systems; D013997:Time Factors
chemical_list: D001426:Bacterial Proteins; C029152:G-substrate; D055767:Immobilized Proteins; D007074:Immunoglobulin G; D009419:Nerve Tissue Proteins; D010969:Plastics