Microfluidics technology: future prospects for molecular diagnostics

Figures & data

Figure 1 Miniaturized analytical systems.

Notes: (A) Gas chromatographic air analyzer on a planar silicon wafer. It was composed of a sample injection system, a 1.5 m circular-spiral column (200×30 µm), and a thermal conductivity detector. (B) Liquid chromatography chip fabricated by Manz et al¹² at Hitachi Central Research Laboratories. The silicon/glass chip included an open-tubular separation column (6 µm×2 µm×150 mm) and an integrated platinum electrode detector. Adapted from de Mello AJ. FOCUS On-chip chromatography: the last twenty years. Lab Chip. 2002;2(3):48N–54N. With permission from The Royal Society of Chemistry. © The Royal Society of Chemistry 2002. http://dx.doi.org/10.1039/b207266c.¹¹

Figure 2 Microfluidic devices for nucleic acid detection.

Notes: (A) A microfluidic device for droplet barcoding ribonucleic acid from individual cells for sequencing. (i) Design of the microfluidic device with microchannels of 80 µm depth (left) and scheme of the on-chip encapsulation process (right). (ii) Micrographs of encapsulation (left) and collection (right) modules. Cells, hydrogel microspheres, and flow direction are indicated by red, blue, and black arrows, respectively. The scale bars represent 100 µm. (B) Schematic views of the microfluidic polymorphism ratio sequencing plate. (i) The top view of the plate containing 96 separation capillaries with a common anode at the center. (ii) Cross-sectional view of the plate. A final layer of 1/8 in. thick Borofloat rings was attached to the top of the plate as the moat rings. (iii, iv) Expanded view of an individual capillary. Each capillary was 17 cm long, 200 µm wide, and 30 µm deep. (C) Schematic view of the multistage volumetric bar chart chip for multiplex, quantitative DNA detection. The oxygen generated during the DNA assay pushes the red ink in the microchannels for visual readouts. (A) Reprinted from Cell, 161(5), Klein AM, Mazutis L, Akartuna I, et al, Droplet barcoding for single-cell transcriptomics applied to embryonic stem cells, 1187–1201, Copyright 2015, with permission from Elsevier.⁵¹ (B) Adapted from Paegel BM, Emrich CA, Wedemayer GJ, Scherer JR, Mathies RA. High throughput DNA sequencing with a microfabricated 96-lane capillary array electrophoresis bioprocessor. Proc Natl Acad Sci. 2002;99(2):574–579. Copyright © 2002, The National Academy of Sciences.⁵⁶ (C) Adapted with permission from Song Y, Wang Y, Qin L. A multistage volumetric bar chart chip for visualized quantification of DNA. J Am Chem Soc. 2013;135(45):16785–16788. Copyright © 2013 American Chemical Society.⁵⁸

Abbreviation: RT, reverse transcription.

Figure 3 Microfluidic devices for protein detection.

Notes: (A) Microfluidic ELISA chip and the schematic illustration of HIV and syphilis detection. Each chip can process seven samples simultaneously. (B) Nanoporous glass-integrated volumetric chip for cancer biomarker detection. (i–iii) The chip design and scanning electron microscope images of the nanoporous glass membrane with scale bars representing 5 μm (ii) and 1 μm (iii). (iv–vi) Sample loading, sandwich ELISA, and result readout. Scale bars=1 cm for (iv) and (vi), respectively. (C) Paper-based analytical device for CEA detection based on FRET using doped UCNPs. (A) Adapted by permission from Macmillan Publishers Ltd: Nat Med. Chin CD, Laksanasopin T, Cheung YK, et al. Microfluidics-based diagnostics of infectious diseases in the developing world. 2011;17(8):1015–1019. Copyright © 2011, Rights Managed by Nature Publishing Group. http://www.nature.com/nm/index.html.⁶⁷ (B) Adapted with permission from Li Y, Xuan J, Song Y, et al. Nanoporous glass integrated in volumetric bar-chart chip for point-of-care diagnostics of non-small cell lung cancer. ACS Nano. 2016;10(1):1640–1647. Copyright © 2016 American Chemical Society.⁶⁹ (C) Adapted from Xu S, Dong B, Zhou D, et al. Paper-based upconversion fluorescence resonance energy transfer biosensor for sensitive detection of multiple cancer biomarkers. Sci Rep. 2016;6:23406. Copyright © 2016, Rights Managed by Nature Publishing Group. The Creative Commons license is available at: https://creativecommons.org/licenses/by/4.0/legalcode.⁷⁴

Abbreviations: BSA, bovine serum albumin; CEA, carcinoembryonic antigen; ELISA, enzyme-linked immunosorbent assay; FITC, fluorescein isothiocyanate; FRET, fluorescence energy transfer; IgG, immunoglobulin G; PtNP, platinum nanoparticle; UCNPs, upconversion nanoparticles.

Figure 4 Point-of-care testing systems.

Notes: (A) Detection of the ovarian cancer biomarker, HE4, by integrating microchip ELISA with cell phone-based colorimetric analysis. (i) Sample and reagent loading. (ii) On-chip sandwich ELISA for color development. (iii) Image acquisition with the built-in camera. (iv) Data processing and result report on the cell phone. (B) Configuration of the smartphone accessory for the detection of Kaposi’s sarcoma associated herpesvirus nucleic acids. (i) An image of the assembled smartphone-based system. (ii) The internal layout of the smartphone accessory. (iii) A sample microfluidic cartridge with 1 cm optical path for sample detection. (C) Configuration of lab-on-a-drone. (A) Adapted from Wang S, Zhao X, Khimji I, et al. Integration of cell phone imaging with microchip ELISA to detect ovarian cancer HE4 biomarker in urine at the point-of-care. Lab Chip. 2011;11(20):3411–3418. With permission from The Royal Society of Chemistry. © The Royal Society of Chemistry 2011. http://dx.doi.org/10.1039/C1LC20479C.⁸⁸ (B) Adapted from Mancuso M, Cesarman E, Erickson D. Detection of Kaposi’s sarcoma associated herpesvirus nucleic acids using a smartphone accessory. Lab Chip. 2014;14(19):3809–3816. With permission from The Royal Society of Chemistry. © The Royal Society of Chemistry 2014. http://dx.doi.org/10.1039/C4LC00517A.⁸⁹ (C) Adapted with permission from Priye A, Wong S, Bi Y, et al. Lab-on-a-drone: toward pinpoint deployment of smartphone-enabled nucleic acid-based diagnostics for mobile health care. Anal Chem. 2016;88(9):4651–4660. Copyright © 2016 American Chemical Society. http://pubs.acs.org/doi/full/10.1021/acs.analchem.5b04153. Permission requests for Figure C should be directed to the American Chemical Society.⁹⁰

Abbreviations: BSA, bovine serum albumin; ELISA, enzyme-linked immunosorbent assay; HE4, human epididymis protein 4; HRP, horseradish peroxidase; LED, light-emitting diode; PCR, polymerase chain reaction; TMB, tetramethylbenzidine.

Table 1 List of selected products for microfluidics-based, molecular diagnostic products in the market

Company	Product	Application
Abaxis	Piccolo Xpress	Blood analysis for lipid, gases, electrolytes, and metabolites
Abbott Point of Care	i-STAT	Hand-held blood analysis for gases, electrolytes, and metabolites
Alere	Triage MeterPro	Cardiovascular and toxicology assays
BD	BD MAX	Real-time PCR for pathogen detection
BioFire Diagnostics	FilmArray	PCR and reverse transcription PCR for respiratory pathogen detection
Cepheid	GeneXpert System	Detection and quantification of nucleic acids
Focus Diagnostics	Integrated Cycler and Simplexa molecular assays	Real-time PCR for pathogen detection
Gyros AB	Gyrolab xPlore	Immunoassays, biomarker monitoring, pharmacokinetics, and toxicokinetics
Micronics	PanNAT	Nucleic acid amplification assay for pathogen detection
RainDance Technologies	RainDrop Plus	Droplet PCR for nucleic acid detection and biomarker monitoring
Roche Diagnostics	cobas Liat	Real-time PCR for pathogen detection
Sphere Medical	Proxima	Blood analysis for gases and electrolytes

Abbreviation: PCR, polymerase chain reaction.

Manz A, Miyahara Y, Miura J, Watanabe Y, Miyagi H, Sato K. Design of an open-tubular column liquid chromatograph using silicon chip technology. Sens Actuators B Chem. 1990;1(1–6):249–255.

 Web of Science ®Google Scholar

de Mello AJ. FOCUS On-chip chromatography: the last twenty years. Lab Chip. 2002;2(3):48N–54N.

 PubMed Web of Science ®Google Scholar

Klein AM, Mazutis L, Akartuna I, et al. Droplet barcoding for single-cell transcriptomics applied to embryonic stem cells. Cell. 2015;161(5):1187–1201.

 PubMed Web of Science ®Google Scholar

Paegel BM, Emrich CA, Wedemayer GJ, Scherer JR, Mathies RA. High throughput DNA sequencing with a microfabricated 96-lane capillary array electrophoresis bioprocessor. Proc Natl Acad Sci. 2002;99(2):574–579.

 Web of Science ®Google Scholar

Song Y, Wang Y, Qin L. A multistage volumetric bar chart chip for visualized quantification of DNA. J Am Chem Soc. 2013;135(45):16785–16788.

 Web of Science ®Google Scholar

Chin CD, Laksanasopin T, Cheung YK, et al. Microfluidics-based diagnostics of infectious diseases in the developing world. Nat Med. 2011;17(8):1015–1019.

 PubMed Web of Science ®Google Scholar

Li Y, Xuan J, Song Y, et al. Nanoporous glass integrated in volumetric bar-chart chip for point-of-care diagnostics of non-small cell lung cancer. ACS Nano. 2016;10(1):1640–1647.

 Web of Science ®Google Scholar

Xu S, Dong B, Zhou D, et al. Paper-based upconversion fluorescence resonance energy transfer biosensor for sensitive detection of multiple cancer biomarkers. Sci Rep. 2016;6:23406.

 Web of Science ®Google Scholar

Wang S, Zhao X, Khimji I, et al. Integration of cell phone imaging with microchip ELISA to detect ovarian cancer HE4 biomarker in urine at the point-of-care. Lab Chip. 2011;11(20):3411–3418.

 PubMed Web of Science ®Google Scholar

Mancuso M, Cesarman E, Erickson D. Detection of Kaposi’s sarcoma associated herpesvirus nucleic acids using a smartphone accessory. Lab Chip. 2014;14(19):3809–3816.

 Web of Science ®Google Scholar

Priye A, Wong S, Bi Y, et al. Lab-on-a-drone: toward pinpoint deployment of smartphone-enabled nucleic acid-based diagnostics for mobile health care. Anal Chem. 2016;88(9):4651–4660.

 PubMed Web of Science ®Google Scholar