Digital extraction techniques
Most real-world chemical analysis applications begin with a complex sample that contains a mixture of many constituents (e.g., serum, pond water, cell lysate, etc.). Complex samples are often impossible to analyze without extraction (or "cleanup") to simplify the sample. Digital microfluidics is proving to be a powerful technology for extraction, which can include non-specific methods (e.g., reversed-phase solid extraction or liquid-liquid extraction) and specific methods (e.g., using immunospecificity to isolate desirable analytes). Papers describing our efforts in this area are listed below.
Elsayed, M.; Bodo, L.; Gaoiran, C.; Keuhnelian, P.; Dosajh, A.; Luk, V.; Schwandt, M.; French, J.L.; Ghosh, A.; Erickson, B.; Charlesworth, A.G.; Millman, J.; Wheeler, A.R. "Toward Analysis at the Point of Need: A Digital Microfluidic Approach to Processing Multi-Source Sexual Assault Samples" Advanced Science 2024, 11, 2405712. Supporting Info. Movie.
Rackus, D.G.; P. S. de Campos, R.; Chan, C.; Karcz, M.M.; Seale, B.; Narahari, T.; Dixon, C.; Chamberlain, M.D.; Wheeler, A.R. "Pre-Concentration by Liquid Intake by Paper (P-CLIP): A New Technique for Large Volumes and Digital Microfluidics" Lab on a Chip, 2017, 17, 2272-2280. Supporting info.
Seale, B.; Lam, C.; Rackus, D.G.; Chamberlain, M.D.; Liu, C.; Wheeler, A.R. "Digital Microfluidics for Immunoprecipitation" Analytical Chemistry, 2016, 88, 10223-10230. Supporting info.
Choi, K.; Boyacı, E.; Kim, J.; Seale, B.; Barrera-Arbelaez, L.; Pawliszyn, J.; Wheeler, A.R. "A Digital Microfluidic Interface between Solid-Phase Microextraction and Liquid Chromatography–Mass Spectrometry" J. Chromatogr. A, 2016, 1444, 1-7. Supporting info.
Lafreniere, N.M.; Mudrik, J.M.; Ng, A.H.C.; Seale, B.; Spooner, N.; Wheeler, A.R. "Attractive Design: An Elution Solvent Optimization Platform for Magnetic-Bead-based Fractionation Using Digital Microfluidics and Design of Experiments" Analytical Chemistry, 2015, 87, 3902-3910.
Ng, A.H.C.; Lee, M.; Choi, K.; Fischer, A.T.; Robinson, J.M.; Wheeler, A.R. "A Digital Microfluidic Platform for the Detection of Rubella Infection and Immunity: A Proof of Concept" Clin. Chem., 2015, 61, 420-429. Supporting info. Supporting video.
Mei, N.; Seale, B.; Ng, A.H.C.; Wheeler, A.R.; Oleschuk, R. "Digital Microfluidic Platform for Human Plasma Protein Depletion" Analytical Chemistry, 2014, 86, 8466-8472. Supporting info. Supporting video.
Mudrik, J.M.; Dryden, M.D.M.; Lafrenière, N.M.; Wheeler, A.R. "Strong and small: strong cation-exchange solid-phase extractions using porous polymer monoliths on a digital microfluidic platform" Canadian Journal of Chemistry 2014, 92, 179-185.
Choi, K.; Ng, A.H.C.; Fobel, R.; Chang-Yen, D.A.; Yarnell, L.E.; Pearson, E.L.; Oleksak, C.M.; Fischer, A.T.; Luoma, R.P.; Robinson, J.M.; Audet, J.; Wheeler, A.R. "Automated Digital Microfluidic Platform for Magnetic-Particle-Based Immunoassays with Optimization by Design of Experiments" Analytical Chemistry 2013, 85, 9638-9646. Supporting info.
Ng, A.H.C.; Choi, K.; Luoma, R.P.; Robinson, J.M.; Wheeler, A.R. "Digital Microfluidic Magnetic Separation for Particle-Based Immunoassays" Analytical Chemistry 2012, 84, 8805-8812. Supporting info.
Yang, H.; Mudrik, J.M.; Jebrail, M.J.; Wheeler, A.R. "A Digital Microfluidic Method for in Situ Formation of Porous Polymer Monoliths with Application to Solid-Phase Extraction" Anal. Chem. 2011, 83, 3824-3830.
Miller, E.M.; Ng, A.H.C.; Uddayasankar, U.; Wheeler, A.R. "A Digital Microfluidic Approach to Heterogeneous Immunoassays" Anal. Bioanal. Chem., 2010, 399, 337-345.
Jebrail, M.; Wheeler, A.R. "A Digital Microfluidic Method for Protein Extraction by Precipitation" Anal. Chem. 2009, 81, 330-335.