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Metzler L, Rehbein U, Schönberg JN, Brandstetter T, Thedieck K, Rühe J. Breaking the Interface: Efficient Extraction of Magnetic Beads from Nanoliter Droplets for Automated Sequential Immunoassays. Anal Chem 2020; 92:10283-10290. [PMID: 32501674 DOI: 10.1021/acs.analchem.0c00187] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Droplet-based microfluidic systems offer a high potential for miniaturization and automation. Therefore, they are becoming an increasingly important tool in analytical chemistry, biosciences, and medicine. Heterogeneous assays commonly utilize magnetic beads as a solid phase. However, the sensitivity of state of the art microfluidic systems is limited by the high bead concentrations required for efficient extraction across the water-oil interface. Furthermore, current systems suffer from a lack of technical solutions for sequential measurements of multiple samples, limiting their throughput and capacity for automation. Taking advantage of the different wetting properties of hydrophilic and hydrophobic areas in the channels, we improve the extraction efficiency of magnetic beads from aqueous nanoliter-sized droplets by 2 orders of magnitude to the low μg/mL range. Furthermore, the introduction of a switchable magnetic trap enables repetitive capture and release of magnetic particles for sequential analysis of multiple samples, enhancing the throughput. In comparison to conventional ELISA-based sandwich immunoassays on microtiter plates, our microfluidic setup offers a 25-50-fold reduction of sample and reagent consumption with up to 50 technical replicates per sample. The enhanced sensitivity and throughput of this system open avenues for the development of automated detection of biomolecules at the nanoliter scale.
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Affiliation(s)
- Lukas Metzler
- Department of Microsystems Engineering, Chemistry & Physics of Interfaces, Albert-Ludwigs-Universität Freiburg, 79110 Freiburg im Breisgau, Baden-Württemberg, Germany
| | - Ulrike Rehbein
- Department of Neuroscience, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26129 Oldenburg, Germany.,Laboratory of Pediatrics, Section Systems Medicine of Metabolism and Signaling, University of Groningen, University Medical Center Groningen, 9713 AV, Groningen, The Netherlands
| | - Jan-Niklas Schönberg
- Department of Microsystems Engineering, Chemistry & Physics of Interfaces, Albert-Ludwigs-Universität Freiburg, 79110 Freiburg im Breisgau, Baden-Württemberg, Germany
| | - Thomas Brandstetter
- Department of Microsystems Engineering, Chemistry & Physics of Interfaces, Albert-Ludwigs-Universität Freiburg, 79110 Freiburg im Breisgau, Baden-Württemberg, Germany
| | - Kathrin Thedieck
- Department of Neuroscience, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26129 Oldenburg, Germany.,Laboratory of Pediatrics, Section Systems Medicine of Metabolism and Signaling, University of Groningen, University Medical Center Groningen, 9713 AV, Groningen, The Netherlands.,Institute of Biochemistry and Center for Molecular Biosciences Innsbruck, University of Innsbruck, 6020 Innsbruck, Austria
| | - Jürgen Rühe
- Department of Microsystems Engineering, Chemistry & Physics of Interfaces, Albert-Ludwigs-Universität Freiburg, 79110 Freiburg im Breisgau, Baden-Württemberg, Germany
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ROCHA FÁBIOR, BATISTA ALEXD, MELCHERT WANESSAR, ZAGATTO ELIASA. Solid-phase extractions in flow analysis. ACTA ACUST UNITED AC 2018; 90:803-824. [DOI: 10.1590/0001-3765201820170513] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 10/09/2017] [Indexed: 12/20/2022]
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