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Alibekova Long M, Benman WKJ, Petrikas N, Bugaj LJ, Hughes AJ. Enhancing Single-Cell Western Blotting Sensitivity Using Diffusive Analyte Blotting and Antibody Conjugate Amplification. Anal Chem 2023; 95:17894-17902. [PMID: 37974303 DOI: 10.1021/acs.analchem.3c04130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
While there are many techniques to achieve highly sensitive, multiplex detection of RNA and DNA from single cells, detecting protein content often suffers from low limits of detection and throughput. Miniaturized, high-sensitivity Western blots on single cells (scWesterns) are attractive because they do not require advanced instrumentation. By physically separating analytes, scWesterns also uniquely mitigate limitations to target protein multiplexing posed by the affinity reagent performance. However, a fundamental limitation of scWesterns is their limited sensitivity for detecting low-abundance proteins, which arises from transport barriers posed by the separation gel against detection species. Here we address the sensitivity by decoupling the electrophoretic separation medium from the detection medium. We transfer scWestern separations to a nitrocellulose blotting medium with distinct mass transfer advantages over traditional in-gel probing, yielding a 5.9-fold improvement in the limit of detection. We next amplify probing of blotted proteins with enzyme-antibody conjugates, which are incompatible with traditional in-gel probing to achieve further improvement in the limit of detection to 1000 molecules, a 120-fold improvement. This enables us to detect 100% of cells in an EGFP-expressing population using fluorescently tagged and enzyme-conjugated antibodies compared to 84.5% of cells using in-gel detection. These results suggest the compatibility of nitrocellulose-immobilized scWesterns with a variety of affinity reagents─not previously accessible for in-gel use─for further signal amplification and detection of low-abundance targets.
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Affiliation(s)
- Mariia Alibekova Long
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Bioengineering Graduate Group, University of Pennsylvania, Philadelphia, Pennsylvania, 19104, United States
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - William K J Benman
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Bioengineering Graduate Group, University of Pennsylvania, Philadelphia, Pennsylvania, 19104, United States
| | - Nathan Petrikas
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Lukasz J Bugaj
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Bioengineering Graduate Group, University of Pennsylvania, Philadelphia, Pennsylvania, 19104, United States
- Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Abramson Cancer Center, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Alex J Hughes
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Bioengineering Graduate Group, University of Pennsylvania, Philadelphia, Pennsylvania, 19104, United States
- Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Center for Soft and Living Matter, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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2
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Long MA, Benman W, Petrikas N, Bugaj LJ, Hughes AJ. Enhancing single-cell western blotting sensitivity using diffusive analyte blotting and antibody conjugate amplification. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.13.544857. [PMID: 37398364 PMCID: PMC10312704 DOI: 10.1101/2023.06.13.544857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
While there are many techniques to achieve highly sensitive, multiplex detection of RNA and DNA from single cells, detecting protein contents often suffers from low limits of detection and throughput. Miniaturized, high-sensitivity western blots on single cells (scWesterns) are attractive since they do not require advanced instrumentation. By physically separating analytes, scWesterns also uniquely mitigate limitations to target protein multiplexing posed by affinity reagent performance. However, a fundamental limitation of scWesterns is their limited sensitivity for detecting low-abundance proteins, which arises from transport barriers posed by the separation gel against detection species. Here we address sensitivity by decoupling the electrophoretic separation medium from the detection medium. We transfer scWestern separations to a nitrocellulose blotting medium with distinct mass transfer advantages over traditional in-gel probing, yielding a 5.9-fold improvement in limit of detection. We next amplify probing of blotted proteins with enzyme-antibody conjugates which are incompatible with traditional in-gel probing to achieve further improvement in the limit of detection to 103 molecules, a 520-fold improvement. This enables us to detect 85% and 100% of cells in an EGFP-expressing population using fluorescently tagged and enzyme-conjugated antibodies respectively, compared to 47% of cells using in-gel detection. These results suggest compatibility of nitrocellulose-immobilized scWesterns with a variety of affinity reagents - not previously accessible for in-gel use - for further signal amplification and detection of low abundance targets.
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Affiliation(s)
- Mariia Alibekova Long
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, 19104, PA, USA
- Bioengineering Graduate Group, University of Pennsylvania, Philadelphia, PA, 19104, PA, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, PA, USA
| | - William Benman
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, 19104, PA, USA
- Bioengineering Graduate Group, University of Pennsylvania, Philadelphia, PA, 19104, PA, USA
| | - Nathan Petrikas
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, 19104, PA, USA
- Currently at Tempus Labs Inc., Chicago, IL, USA
| | - Lukasz J. Bugaj
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, 19104, PA, USA
- Bioengineering Graduate Group, University of Pennsylvania, Philadelphia, PA, 19104, PA, USA
- Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Abramson Cancer Center, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Alex J. Hughes
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, 19104, PA, USA
- Bioengineering Graduate Group, University of Pennsylvania, Philadelphia, PA, 19104, PA, USA
- Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Center for Soft and Living Matter, University of Pennsylvania, Philadelphia, PA, 19104, USA
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3
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Desire CT, Arrua RD, Strudwick XL, Kopecki Z, Cowin AJ, Hilder EF. The development of microfluidic-based western blotting: Technical advances and future perspectives. J Chromatogr A 2023; 1691:463813. [PMID: 36709548 DOI: 10.1016/j.chroma.2023.463813] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/11/2023] [Accepted: 01/18/2023] [Indexed: 01/22/2023]
Abstract
Over the past two decades significant technical advancement in the field of western blotting has been made possible through the utilization of microfluidic technologies. In this review we provide a critical overview of these advancements, highlighting the advantages and disadvantages of each approach. Particular attention is paid to the development of now commercially available systems, including those for single cell analysis. This review also discusses more recent developments, including algorithms for automation and/or improved quantitation, the utilization of different materials/chemistries, use of projection electrophoresis, and the development of triBlots. Finally, the review includes commentary on future advances in the field based on current developments, and the potential of these systems for use as point-of-care devices in healthcare.
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Affiliation(s)
- Christopher T Desire
- Future Industries Institute, University of South Australia, GPO Box 2471, Adelaide, SA 5001, Australia
| | - R Dario Arrua
- Future Industries Institute, University of South Australia, GPO Box 2471, Adelaide, SA 5001, Australia
| | - Xanthe L Strudwick
- Future Industries Institute, University of South Australia, GPO Box 2471, Adelaide, SA 5001, Australia
| | - Zlatko Kopecki
- Future Industries Institute, University of South Australia, GPO Box 2471, Adelaide, SA 5001, Australia
| | - Allison J Cowin
- Future Industries Institute, University of South Australia, GPO Box 2471, Adelaide, SA 5001, Australia
| | - Emily F Hilder
- Future Industries Institute, University of South Australia, GPO Box 2471, Adelaide, SA 5001, Australia.
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4
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Xie H, Ding X. The Intriguing Landscape of Single-Cell Protein Analysis. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2105932. [PMID: 35199955 PMCID: PMC9036017 DOI: 10.1002/advs.202105932] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/27/2022] [Indexed: 05/15/2023]
Abstract
Profiling protein expression at single-cell resolution is essential for fundamental biological research (such as cell differentiation and tumor microenvironmental examination) and clinical precision medicine where only a limited number of primary cells are permitted. With the recent advances in engineering, chemistry, and biology, single-cell protein analysis methods are developed rapidly, which enable high-throughput and multiplexed protein measurements in thousands of individual cells. In combination with single cell RNA sequencing and mass spectrometry, single-cell multi-omics analysis can simultaneously measure multiple modalities including mRNAs, proteins, and metabolites in single cells, and obtain a more comprehensive exploration of cellular signaling processes, such as DNA modifications, chromatin accessibility, protein abundance, and gene perturbation. Here, the recent progress and applications of single-cell protein analysis technologies in the last decade are summarized. Current limitations, challenges, and possible future directions in this field are also discussed.
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Affiliation(s)
- Haiyang Xie
- State Key Laboratory of Oncogenes and Related GenesInstitute for Personalized MedicineSchool of Biomedical EngineeringShanghai Jiao Tong UniversityShanghai200030China
| | - Xianting Ding
- State Key Laboratory of Oncogenes and Related GenesInstitute for Personalized MedicineSchool of Biomedical EngineeringShanghai Jiao Tong UniversityShanghai200030China
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Hennig S, Shu Z, Gutzweiler L, Koltay P, von Stetten F, Zengerle R, Früh SM. Paper-based open microfluidic platform for protein electrophoresis and immunoprobing. Electrophoresis 2021; 43:621-631. [PMID: 34902175 DOI: 10.1002/elps.202100327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 12/02/2021] [Accepted: 12/02/2021] [Indexed: 11/10/2022]
Abstract
Protein electrophoresis and immunoblotting are indispensable analytical tools for the characterization of proteins and posttranslational modifications in complex sample matrices. Owing to the lack of automation, commonly employed slab-gel systems suffer from high time demand, significant sample/antibody consumption, and limited reproducibility. To overcome these limitations, we developed a paper-based open microfluidic platform for electrophoretic protein separation and subsequent transfer to protein-binding membranes for immunoprobing. Electrophoresis microstructures were digitally printed into cellulose acetate membranes that provide mechanical stability while maintaining full accessibility of the microstructures for consecutive immunological analysis. As a proof-of-concept, we demonstrate separation of fluorescently labeled marker proteins in a wide molecular weight range (15-120 kDa) within only 15 min, reducing the time demand for the entire workflow (from sample preparation to immunoassay) to approximately one hour. Sample consumption was reduced 10- to 150-fold compared to slab-gel systems, owing to system miniaturization. Moreover, we successfully applied the paper-based approach to complex samples such as crude bacterial cell extracts. We envisage that this platform will find its use in protein analysis workflows for scarce and precious samples, providing a unique opportunity to extract profound immunological information from limited sample amounts in a fast fashion with minimal hands-on time.
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Affiliation(s)
| | - Zhe Shu
- Hahn-Schickard, Freiburg, Germany.,Laboratory for MEMS Applications, IMTEK - Department of Microsystems Engineering, University of Freiburg, Freiburg, Germany
| | | | - Peter Koltay
- Hahn-Schickard, Freiburg, Germany.,Laboratory for MEMS Applications, IMTEK - Department of Microsystems Engineering, University of Freiburg, Freiburg, Germany
| | - Felix von Stetten
- Hahn-Schickard, Freiburg, Germany.,Laboratory for MEMS Applications, IMTEK - Department of Microsystems Engineering, University of Freiburg, Freiburg, Germany
| | - Roland Zengerle
- Hahn-Schickard, Freiburg, Germany.,Laboratory for MEMS Applications, IMTEK - Department of Microsystems Engineering, University of Freiburg, Freiburg, Germany
| | - Susanna M Früh
- Hahn-Schickard, Freiburg, Germany.,Laboratory for MEMS Applications, IMTEK - Department of Microsystems Engineering, University of Freiburg, Freiburg, Germany
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6
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Fan Z, Lin Z, Wang Z, Wang J, Xie M, Zhao J, Zhang K, Huang W. Dual-Wavelength Electrochemiluminescence Ratiometric Biosensor for NF-κB p50 Detection with Dimethylthiodiaminoterephthalate Fluorophore and Self-Assembled DNA Tetrahedron Nanostructures Probe. ACS APPLIED MATERIALS & INTERFACES 2020; 12:11409-11418. [PMID: 32067445 DOI: 10.1021/acsami.0c01243] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
In this work, we fabricated a dual-wavelength electrochemiluminescence ratiometric biosensor based on electrochemiluminescent resonance energy transfer (ECL-RET). In this biosensor, Au nanoparticle-loaded graphitic phase carbon nitride (Au-g-C3N4) as a donor and Au-modified dimethylthiodiaminoterephthalate (TAT) analogue (Au@TAT) as an acceptor were investigated for the first time. Besides, tetrahedron DNA probe was immobilized onto Au-g-C3N4 to improve the binding efficiency of the transcription factor and ECL ratiometric changes on the basis of the ratio of ECL intensities at 595 and 460 nm, which were obtained through the formation of a sandwich structure of DNA probe-antigen-antibody. Our biosensor achieved the assay of NF-κB p50 with a detection limit of 5.8 pM as well as high stability and specificity.
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Affiliation(s)
- Zhenqiang Fan
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, Jiangsu, China
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, P. R. China
| | - Zongqiong Lin
- Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an 710072, Shaanxi, P. R. China
| | - Zepeng Wang
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, P. R. China
| | - Jianfeng Wang
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, P. R. China
| | - Minhao Xie
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, Jiangsu, China
- Department of Radiopharmaceuticals, School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
| | - Jianfeng Zhao
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, Jiangsu, China
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, P. R. China
| | - Kai Zhang
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, Jiangsu, China
- Department of Radiopharmaceuticals, School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
| | - Wei Huang
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, P. R. China
- Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an 710072, Shaanxi, P. R. China
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7
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Park K, Lee Y, Seo J. Recent Advances in High-throughput Platforms with Engineered Biomaterial Microarrays for Screening of Cell and Tissue Behavior. Curr Pharm Des 2019; 24:5458-5470. [DOI: 10.2174/1381612825666190207093438] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 02/02/2019] [Indexed: 02/06/2023]
Abstract
In the last decades, bioengineers have developed myriad biomaterials for regenerative medicine. Development of screening techniques is essential for understanding complex behavior of cells in the biological microenvironments. Conventional approaches to the screening of cellular behavior in vitro have limitations in terms of accuracy, reusability, labor-intensive screening, and versatility. Thus, drug screening and toxicology test through in vitro screening platforms have been underwhelming. Recent advances in the high-throughput screening platforms somewhat overcome the limitations of in vitro screening platforms via repopulating human tissues’ biophysical and biomchemical microenvironments with the ability to continuous monitoring of miniaturized human tissue behavior. Herein, we review current trends in the screening platform in which a high-throughput system composed of engineered microarray devices is developed to investigate cell-biomaterial interaction. Furthermore, diverse methods to achieve continuous monitoring of cell behavior via developments of biosensor integrated high-throughput platforms, and future perspectives on high-throughput screening will be provided.
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Affiliation(s)
- Kijun Park
- School of Electrical and Electronic Engineering, Yonsei University, Seoul, 03722, Korea
| | - Yeontaek Lee
- School of Electrical and Electronic Engineering, Yonsei University, Seoul, 03722, Korea
| | - Jungmok Seo
- School of Electrical and Electronic Engineering, Yonsei University, Seoul, 03722, Korea
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8
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Samal P, van Blitterswijk C, Truckenmüller R, Giselbrecht S. Grow with the Flow: When Morphogenesis Meets Microfluidics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1805764. [PMID: 30767289 DOI: 10.1002/adma.201805764] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 01/04/2019] [Indexed: 06/09/2023]
Abstract
Developmental biology has advanced the understanding of the intricate and dynamic processes involved in the formation of an organism from a single cell. However, many gaps remain in the knowledge of embryonic development, especially regarding tissue morphogenesis. A possible approach to mimic such phenomena uses pluripotent stem cells in in vitro morphogenetic models. Herein, these systems are summarized with emphasis on the ability to better manipulate and control cellular interfaces with either liquid or solid materials using microengineered tools, which is critical for attaining deeper insights into pattern formation and stem cell differentiation during organogenesis. The role of conventional and customized cell-culture systems in supporting important advances in the field of morphogenesis is discussed, and the fascinating role that material sciences and microengineering currently play and are expected to play in the future is highlighted. In conclusion, it is proffered that continued microfluidics innovations when applied to morphogenesis promise to provide important insights to advance many multidisciplinary fields, including regenerative medicine.
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Affiliation(s)
- Pinak Samal
- Department of Complex Tissue Engineering, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, 6229 ER, Maastricht, The Netherlands
| | - Clemens van Blitterswijk
- Department of Complex Tissue Engineering, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, 6229 ER, Maastricht, The Netherlands
| | - Roman Truckenmüller
- Department of Complex Tissue Engineering, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, 6229 ER, Maastricht, The Netherlands
| | - Stefan Giselbrecht
- Department of Complex Tissue Engineering, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, 6229 ER, Maastricht, The Netherlands
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9
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Shin SR, Kilic T, Zhang YS, Avci H, Hu N, Kim D, Branco C, Aleman J, Massa S, Silvestri A, Kang J, Desalvo A, Hussaini MA, Chae S, Polini A, Bhise N, Hussain MA, Lee H, Dokmeci MR, Khademhosseini A. Label-Free and Regenerative Electrochemical Microfluidic Biosensors for Continual Monitoring of Cell Secretomes. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2017; 4:1600522. [PMID: 28546915 PMCID: PMC5441508 DOI: 10.1002/advs.201600522] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 01/15/2017] [Indexed: 05/04/2023]
Abstract
Development of an efficient sensing platform capable of continual monitoring of biomarkers is needed to assess the functionality of the in vitro organoids and to evaluate their biological responses toward pharmaceutical compounds or chemical species over extended periods of time. Here, a novel label-free microfluidic electrochemical (EC) biosensor with a unique built-in on-chip regeneration capability for continual measurement of cell-secreted soluble biomarkers from an organoid culture in a fully automated manner without attenuating the sensor sensitivity is reported. The microfluidic EC biosensors are integrated with a human liver-on-a-chip platform for continual monitoring of the metabolic activity of the organoids by measuring the levels of secreted biomarkers for up to 7 d, where the metabolic activity of the organoids is altered by a systemically applied drug. The variations in the biomarker levels are successfully measured by the microfluidic regenerative EC biosensors and agree well with cellular viability and enzyme-linked immunosorbent assay analyses, validating the accuracy of the unique sensing platform. It is believed that this versatile and robust microfluidic EC biosensor that is capable of automated and continual detection of soluble biomarkers will find widespread use for long-term monitoring of human organoids during drug toxicity studies or efficacy assessments of in vitro platforms.
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Xie N, Huang J, Yang X, Yang Y, Quan K, Ou M, Fang H, Wang K. Competition-Mediated FRET-Switching DNA Tetrahedron Molecular Beacon for Intracellular Molecular Detection. ACS Sens 2016. [DOI: 10.1021/acssensors.6b00593] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Nuli Xie
- State Key Laboratory of Chemo/Biosensing
and Chemometrics, College of Chemistry and Chemical Engineering, Key
Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan
Province, Hunan University, Changsha 410082, China
| | - Jin Huang
- State Key Laboratory of Chemo/Biosensing
and Chemometrics, College of Chemistry and Chemical Engineering, Key
Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan
Province, Hunan University, Changsha 410082, China
| | - Xiaohai Yang
- State Key Laboratory of Chemo/Biosensing
and Chemometrics, College of Chemistry and Chemical Engineering, Key
Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan
Province, Hunan University, Changsha 410082, China
| | - Yanjing Yang
- State Key Laboratory of Chemo/Biosensing
and Chemometrics, College of Chemistry and Chemical Engineering, Key
Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan
Province, Hunan University, Changsha 410082, China
| | - Ke Quan
- State Key Laboratory of Chemo/Biosensing
and Chemometrics, College of Chemistry and Chemical Engineering, Key
Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan
Province, Hunan University, Changsha 410082, China
| | - Min Ou
- State Key Laboratory of Chemo/Biosensing
and Chemometrics, College of Chemistry and Chemical Engineering, Key
Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan
Province, Hunan University, Changsha 410082, China
| | - Hongmei Fang
- State Key Laboratory of Chemo/Biosensing
and Chemometrics, College of Chemistry and Chemical Engineering, Key
Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan
Province, Hunan University, Changsha 410082, China
| | - Kemin Wang
- State Key Laboratory of Chemo/Biosensing
and Chemometrics, College of Chemistry and Chemical Engineering, Key
Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan
Province, Hunan University, Changsha 410082, China
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11
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Sanders BJ, Kim DC, Dunn RC. Recent Advances in Microscale Western Blotting. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2016; 8:7002-7013. [PMID: 28392839 PMCID: PMC5383213 DOI: 10.1039/c6ay01947a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Western blotting is a ubiquitous tool used extensively in the clinical and research settings to identify proteins and characterize their levels. It has rapidly become a mainstay in research laboratories due to its specificity, low cost, and ease of use. The specificity arises from the orthogonal processes used to identify proteins. Samples are first separated based on size and then probed with antibodies specific for the protein of interest. This confirmatory approach helps avoid pitfalls associated with antibody cross-reactivity and specificity issues. While the technique has evolved since its inception, the last decade has witnessed a paradigm shift in Western blotting technology. The introduction of capillary and microfluidic platforms has significantly decreased time and sample requirements while enabling high-throughput capabilities. These advances have enabled Western analysis down to the single cell level in highly parallel formats, opening vast new opportunities for studying cellular heterogeneity. Recent innovations in microscale Western blotting are surveyed, and the potential for enhancing detection using advances in label-free biosensing is briefly discussed.
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Affiliation(s)
- Brittany J Sanders
- Ralph Adams Institute of Bioanalytical Chemistry, Department of Chemistry, University of Kansas
| | - Daniel C Kim
- Ralph Adams Institute of Bioanalytical Chemistry, Department of Chemistry, University of Kansas
| | - Robert C Dunn
- Ralph Adams Institute of Bioanalytical Chemistry, Department of Chemistry, University of Kansas
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12
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Jin S, Furtaw MD, Chen H, Lamb DT, Ferguson SA, Arvin NE, Dawod M, Kennedy RT. Multiplexed Western Blotting Using Microchip Electrophoresis. Anal Chem 2016; 88:6703-10. [PMID: 27270033 DOI: 10.1021/acs.analchem.6b00705] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Western blotting is a commonly used protein assay that combines the selectivity of electrophoretic separation and immunoassay. The technique is limited by long time, manual operation with mediocre reproducibility, and large sample consumption, typically 10-20 μg per assay. Western blots are also usually used to measure only one protein per assay with an additional housekeeping protein for normalization. Measurement of multiple proteins is possible; however, it requires stripping membranes of antibody and then reprobing with a second antibody. Miniaturized alternatives to Western blot based on microfluidic or capillary electrophoresis have been developed that enable higher-throughput, automation, and greater mass sensitivity. In one approach, proteins are separated by electrophoresis on a microchip that is dragged along a polyvinylidene fluoride membrane so that as proteins exit the chip they are captured on the membrane for immunoassay. In this work, we improve this method to allow multiplexed protein detection. Multiple injections made from the same sample can be deposited in separate tracks so that each is probed with a different antibody. To further enhance multiplexing capability, the electrophoresis channel dimensions were optimized for resolution while keeping separation and blotting times to less than 8 min. Using a 15 μm deep × 50 μm wide × 8.6 cm long channel, it is possible to achieve baseline resolution of proteins that differ by 5% in molecular weight, e.g., ERK1 (44 kDa) from ERK2 (42 kDa). This resolution allows similar proteins detected by cross-reactive antibodies in a single track. We demonstrate detection of 11 proteins from 9 injections from a single Jurkat cell lysate sample consisting of 400 ng of total protein using this procedure. Thus, multiplexed Western blots are possible without cumbersome stripping and reprobing steps.
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Affiliation(s)
- Shi Jin
- Department of Chemistry, University of Michigan , Ann Arbor, Michigan 48109, United States
| | - Michael D Furtaw
- LI-COR Biosciences , 4647 Superior Street, Lincoln, Nebraska 68504, United States
| | - Huaxian Chen
- LI-COR Biosciences , 4647 Superior Street, Lincoln, Nebraska 68504, United States
| | - Don T Lamb
- LI-COR Biosciences , 4647 Superior Street, Lincoln, Nebraska 68504, United States
| | - Stephen A Ferguson
- Department of Chemistry, University of Michigan , Ann Arbor, Michigan 48109, United States
| | - Natalie E Arvin
- Department of Chemistry, University of Michigan , Ann Arbor, Michigan 48109, United States
| | - Mohamed Dawod
- Department of Chemistry, University of Michigan , Ann Arbor, Michigan 48109, United States
| | - Robert T Kennedy
- Department of Chemistry, University of Michigan , Ann Arbor, Michigan 48109, United States
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14
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Present state of microchip electrophoresis: state of the art and routine applications. J Chromatogr A 2014; 1382:66-85. [PMID: 25529267 DOI: 10.1016/j.chroma.2014.11.034] [Citation(s) in RCA: 130] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Revised: 11/07/2014] [Accepted: 11/12/2014] [Indexed: 12/20/2022]
Abstract
Microchip electrophoresis (MCE) was one of the earliest applications of the micro-total analysis system (μ-TAS) concept, whose aim is to reduce analysis time and reagent and sample consumption while increasing throughput and portability by miniaturizing analytical laboratory procedures onto a microfluidic chip. More than two decades on, electrophoresis remains the most common separation technique used in microfluidic applications. MCE-based instruments have had some commercial success and have found application in many disciplines. This review will consider the present state of MCE including recent advances in technology and both novel and routine applications in the laboratory. We will also attempt to assess the impact of MCE in the scientific community and its prospects for the future.
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15
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Gerver R, Herr AE. Microfluidic Western blotting of low-molecular-mass proteins. Anal Chem 2014; 86:10625-32. [PMID: 25268977 PMCID: PMC4222625 DOI: 10.1021/ac5024588] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 09/30/2014] [Indexed: 12/01/2022]
Abstract
We describe a microfluidic Western blot assay (μWestern) using a Tris tricine discontinuous buffer system suitable for analyses of a wide molecular mass range (6.5-116 kDa). The Tris tricine μWestern is completed in an enclosed, straight glass microfluidic channel housing a photopatterned polyacrylamide gel that incorporates a photoactive benzophenone methacrylamide monomer. Upon brief ultraviolet (UV) light exposure, the hydrogel toggles from molecular sieving for size-based separation to a covalent immobilization scaffold for in situ antibody probing. Electrophoresis controls all assay stages, affording purely electronic operation with no pumps or valves needed for fluid control. Electrophoretic introduction of antibody into and along the molecular sieving gel requires that the probe must traverse through (i) a discontinuous gel interface central to the transient isotachophoresis used to achieve high-performance separations and (ii) the full axial length of the separation gel. In-channel antibody probing of small molecular mass species is especially challenging, since the gel must effectively sieve small proteins while permitting effective probing with large-molecular-mass antibodies. To create a well-controlled gel interface, we introduce a fabrication method that relies on a hydrostatic pressure mismatch between the buffer and polymer precursor solution to eliminate the interfacial pore-size control issues that arise when a polymerizing polymer abuts a nonpolymerizing polymer solution. Combined with a new swept antibody probe plug delivery scheme, the Tris tricine μWestern blot enables 40% higher separation resolution as compared to a Tris glycine system, destacking of proteins down to 6.5 kDa, and a 100-fold better signal-to-noise ratio (SNR) for small pore gels, expanding the range of applicable biological targets.
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Affiliation(s)
- Rachel
E. Gerver
- University of California Berkeley
and University of California San
Francisco Graduate Program in Bioengineering, and Department of Bioengineering, University of California Berkeley, Berkeley, California 94720, United States
| | - Amy E. Herr
- University of California Berkeley
and University of California San
Francisco Graduate Program in Bioengineering, and Department of Bioengineering, University of California Berkeley, Berkeley, California 94720, United States
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16
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Chung M, Kim D, Herr AE. Polymer sieving matrices in microanalytical electrophoresis. Analyst 2014; 139:5635-54. [DOI: 10.1039/c4an01179a] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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17
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Eker B, Temiz Y, Delamarche E. Heterogeneous integration of gels into microfluidics using a mesh carrier. Biomed Microdevices 2014; 16:829-35. [DOI: 10.1007/s10544-014-9886-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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18
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Tentori AM, Herr AE. Performance implications of chemical mobilization after microchannel IEF. Electrophoresis 2014; 35:1453-60. [DOI: 10.1002/elps.201400023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 02/18/2014] [Accepted: 02/19/2014] [Indexed: 11/08/2022]
Affiliation(s)
- Augusto M. Tentori
- The UC Berkeley/UCSF Graduate Program in Bioengineering; Berkeley CA USA
| | - Amy E. Herr
- The UC Berkeley/UCSF Graduate Program in Bioengineering; Berkeley CA USA
- Department of Bioengineering; UC Berkeley; Berkeley CA USA
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19
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Chang HN, Leroueil PR, Selwa K, Gasper CJ, Tsuchida RE, Wang JJ, McHugh WM, Cornell TT, Baker JR, Goonewardena SN. Profiling inflammatory responses with microfluidic immunoblotting. PLoS One 2013; 8:e81889. [PMID: 24312374 PMCID: PMC3842271 DOI: 10.1371/journal.pone.0081889] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Accepted: 10/17/2013] [Indexed: 11/18/2022] Open
Abstract
Rapid profiling of signaling pathways has been a long sought after goal in biological sciences and clinical medicine. To understand these signaling pathways, their protein components must be profiled. The protein components of signaling pathways are typically profiled with protein immunoblotting. Protein immunoblotting is a powerful technique but has several limitations including the large sample requirements, high amounts of antibody, and limitations in assay throughput. To overcome some of these limitations, we have designed a microfluidic protein immunoblotting device to profile multiple signaling pathways simultaneously. We show the utility of this approach by profiling inflammatory signaling pathways (NFκB, JAK-STAT, and MAPK) in cell models and human samples. The microfluidic immunoblotting device can profile proteins and protein modifications with 5380-fold less antibody compared to traditional protein immunoblotting. Additionally, this microfluidic device interfaces with commonly available immunoblotting equipment, has the ability to multiplex, and is compatible with several protein detection methodologies. We anticipate that this microfluidic device will complement existing techniques and is well suited for life science applications.
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Affiliation(s)
- Huai-Ning Chang
- Michigan Nanotechnology Institute for Medicine and Biological Sciences, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Pascale R. Leroueil
- Michigan Nanotechnology Institute for Medicine and Biological Sciences, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Katherine Selwa
- Michigan Nanotechnology Institute for Medicine and Biological Sciences, University of Michigan, Ann Arbor, Michigan, United States of America
| | - C. J. Gasper
- Michigan Nanotechnology Institute for Medicine and Biological Sciences, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Ryan E. Tsuchida
- Michigan Nanotechnology Institute for Medicine and Biological Sciences, University of Michigan, Ann Arbor, Michigan, United States of America
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Jason J. Wang
- Michigan Nanotechnology Institute for Medicine and Biological Sciences, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Walker M. McHugh
- Division of Pediatric Critical Care Medicine, Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Timothy T. Cornell
- Division of Pediatric Critical Care Medicine, Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, Michigan, United States of America
| | - James R. Baker
- Michigan Nanotechnology Institute for Medicine and Biological Sciences, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Sascha N. Goonewardena
- Michigan Nanotechnology Institute for Medicine and Biological Sciences, University of Michigan, Ann Arbor, Michigan, United States of America
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail:
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20
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Araz MK, Apori AA, Salisbury CM, Herr AE. Microfluidic barcode assay for antibody-based confirmatory diagnostics. LAB ON A CHIP 2013; 13:3910-3920. [PMID: 23925585 DOI: 10.1039/c3lc50229e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Confirmatory diagnostics offer high clinical sensitivity and specificity typically by assaying multiple disease biomarkers. Employed in clinical laboratory settings, such assays confirm a positive screening diagnostic result. These important multiplexed confirmatory assays require hours to complete. To address this performance gap, we introduce a simple 'single inlet, single outlet' microchannel architecture with multiplexed analyte detection capability. A streptavidin-functionalized, channel-filling polyacrylamide gel in a straight glass microchannel operates as a 3D scaffold for a purely electrophoretic yet heterogeneous immunoassay. Biotin and biotinylated capture reagents are patterned in discrete regions along the axis of the microchannel resulting in a barcode-like pattern of reagents and spacers. To characterize barcode fabrication, an empirical study of patterning behaviour was conducted across a range of electromigration and binding reaction timescales. We apply the heterogeneous barcode immunoassay to detection of human antibodies against hepatitis C virus and human immunodeficiency virus antigens. Serum was electrophoresed through the barcode patterned gel, allowing capture of antibody targets. We assess assay performance across a range of Damkohler numbers. Compared to clinical immunoblots that require 4-10 h long sample incubation steps with concomitant 8-20 h total assay durations; directed electromigration and reaction in the microfluidic barcode assay leads to a 10 min sample incubation step and a 30 min total assay duration. Further, the barcode assay reports clinically relevant sensitivity (25 ng ml(-1) in 2% human sera) comparable to standard HCV confirmatory diagnostics. Given the low voltage, low power and automated operation, we see the streamlined microfluidic barcode assay as a step towards rapid confirmatory diagnostics for a low-resource clinical laboratory setting.
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Affiliation(s)
- M Kursad Araz
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA, USA
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21
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22
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Abstract
With the experimental tools and knowledge that have accrued from a long history of reductionist biology, we can now start to put the pieces together and begin to understand how biological systems function as an integrated whole. Here, we describe how microfabricated tools have demonstrated promise in addressing experimental challenges in throughput, resolution, and sensitivity to support systems-based approaches to biological understanding.
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Affiliation(s)
- Mei Zhan
- Interdisciplinary Program in Bioengineering, Georgia Institute of Technology, Atlanta, Georgia, United States
| | - Loice Chingozha
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States
| | - Hang Lu
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States
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23
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Abstract
Perhaps paradoxically, we argue that the biological sciences are "data-limited". In contrast to the glut of DNA sequencing data available, high-throughput protein analysis is expensive and largely inaccessible. Hence, we posit that access to robust protein-level data is inadequate. Here, we use the framework of the formal engineering design process to both identify and understand the problems facing measurement science in the 21st century. In particular, discussion centers on the notable challenge of realizing protein analyses that are as effective (and transformative) as genomics tools. This Perspective looks through the lens of a case study on protein biomarker validation and verification, to highlight the importance of iterative design in realizing significant advances over currently available measurement capabilities in the candidate or targeted proteomics space. The Perspective follows a podium presentation given by the author at The 16th International Conference on Miniaturized Systems for Chemistry and Life Sciences (μTAS 2012), specifically focusing on novel targeted proteomic measurement tools based in microfluidic design. The role of unmet needs identification, iteration in concept generation and development, and the existing gap in rapid prototyping tools for separations are all discussed.
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Affiliation(s)
- Amy E Herr
- The UC Berkeley/UCSF Graduate Program in Bioengineering, Berkeley, California, United States.
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24
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Chung M, Kim D, Herr AE. Microchamber Western Blotting Using Poly-l-Lysine Conjugated Polyacrylamide Gel for Blotting of Sodium Dodecyl Sulfate Coated Proteins. Anal Chem 2013; 85:7753-61. [DOI: 10.1021/ac401012j] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Minsub Chung
- Department of Bioengineering, University of California, Berkeley, California 94720,
United States
| | - Dohyun Kim
- Department of Bioengineering, University of California, Berkeley, California 94720,
United States
- Department
of Mechanical Engineering, Myongji University, Yongin, Gyeonggi-do 449-728, South
Korea
| | - Amy E. Herr
- Department of Bioengineering, University of California, Berkeley, California 94720,
United States
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25
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Kim D, Herr AE. Protein immobilization techniques for microfluidic assays. BIOMICROFLUIDICS 2013; 7:41501. [PMID: 24003344 PMCID: PMC3747845 DOI: 10.1063/1.4816934] [Citation(s) in RCA: 219] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2013] [Accepted: 07/16/2013] [Indexed: 05/07/2023]
Abstract
Microfluidic systems have shown unequivocal performance improvements over conventional bench-top assays across a range of performance metrics. For example, specific advances have been made in reagent consumption, throughput, integration of multiple assay steps, assay automation, and multiplexing capability. For heterogeneous systems, controlled immobilization of reactants is essential for reliable, sensitive detection of analytes. In most cases, protein immobilization densities are maximized, while native activity and conformation are maintained. Immobilization methods and chemistries vary significantly depending on immobilization surface, protein properties, and specific assay goals. In this review, we present trade-offs considerations for common immobilization surface materials. We overview immobilization methods and chemistries, and discuss studies exemplar of key approaches-here with a specific emphasis on immunoassays and enzymatic reactors. Recent "smart immobilization" methods including the use of light, electrochemical, thermal, and chemical stimuli to attach and detach proteins on demand with precise spatial control are highlighted. Spatially encoded protein immobilization using DNA hybridization for multiplexed assays and reversible protein immobilization surfaces for repeatable assay are introduced as immobilization methods. We also describe multifunctional surface coatings that can perform tasks that were, until recently, relegated to multiple functional coatings. We consider the microfluidics literature from 1997 to present and close with a perspective on future approaches to protein immobilization.
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Affiliation(s)
- Dohyun Kim
- Department of Mechanical Engineering, Myongji University, 116 Myongji-ro, Cheoin-gu, Yongin-si, Gyeonggi-do 449-728, South Korea
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26
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Jin S, Anderson GJ, Kennedy RT. Western blotting using microchip electrophoresis interfaced to a protein capture membrane. Anal Chem 2013; 85:6073-9. [PMID: 23672369 DOI: 10.1021/ac400940x] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Western blotting is a commonly used assay for proteins. Despite the utility of the method, it is also characterized by long analysis times, manual operation, and lack of established miniaturized counterpart. We report a new way to Western blot that addresses these limitations. In the method, sodium dodecyl sulfate (SDS)-protein complexes are separated by sieving electrophoresis in a microfluidic device or chip. The chip is interfaced to a moving membrane so that proteins are captured in discrete zones as they migrate from the chip. Separations of SDS-protein complexes in the molecular weight range of 11-155 kDa were completed in 2 min with 4 × 10(4) theoretical plates at 460 V/cm. Migration time and peak area relative standard deviations were 3-6% and 0.2%, respectively. Detection limit for actin was 0.7 nM. Assays for actin, AMP-kinase, carbonic anhydrase, and lysozyme are shown to demonstrate versatility of the method. Total analysis time including immunoassay was 22-32 min for a single sample. Because processing membrane for immunoassay is the slow step of the assay, sequential injections from different reservoirs on the chip and capture in different tracks on the same membrane allow increased throughput. As a demonstration, 9 injections were collected on one membrane and analyzed in 43 min (~5 min/sample). Further improvements in throughput are possible with more reservoirs or parallel channels.
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Affiliation(s)
- Shi Jin
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
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27
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Tentori AM, Hughes AJ, Herr AE. Microchamber integration unifies distinct separation modes for two-dimensional electrophoresis. Anal Chem 2013; 85:4538-45. [PMID: 23565932 PMCID: PMC3714212 DOI: 10.1021/ac4001767] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
By combining isoelectric focusing (IEF) with subsequent gel electrophoresis, two-dimensional electrophoresis (2DE) affords more specific characterization of proteins than each constituent unit separation. In a new approach to integrating the two assay dimensions in a microscope slide-sized glass device, we introduce microfluidic 2DE using photopatterned polyacrylamide (PA) gel elements housed in a millimeter-scale, 20-μm-deep chamber. The microchamber minimizes information loss inherent to channel network architectures commonly used for microfluidic 2DE. To define the IEF axis along a "lane" at the top of the chamber, we used free solution carrier ampholytes and immobilized acrylamido buffers in the PA gels. This approach yielded high-resolution (0.1 pH unit) and rapid (<20 min) IEF. Next, protein transfer to the second dimension was accomplished by chemical mobilization perpendicular to the IEF axis. Mobilization drove focused proteins off the IEF lane and into a region for protein gel electrophoresis. Using fluorescently labeled proteins, we observed transfer-induced band broadening factors ~7.5-fold lower than those observed in microchannel networks. Both native polyacrylamide gel electrophoresis (PAGE) and pore-limit electrophoresis (PLE) were studied as the second assay dimension and completed in <15 min. PLE yields protein molecular mass information without the need for ionic surfactant or reducing agents, simplifying device design and operation. Microchamber-based 2DE unifies two independent separation dimensions in a single device with minimal transfer-associated information losses. Peak capacities for the total assay ranged from 256 to 35 with <1 h assay duration. The rapid microchamber 2DE assay has the potential to bridge an existing gap in targeted proteomics for protein biomarker validation and systems biology that may complement recent innovation in mass spectrometry.
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Affiliation(s)
- Augusto M. Tentori
- The UC Berkeley/UCSF Graduate Program in Bioengineering, Berkeley, CA, USA
| | - Alex J. Hughes
- The UC Berkeley/UCSF Graduate Program in Bioengineering, Berkeley, CA, USA
| | - Amy E. Herr
- The UC Berkeley/UCSF Graduate Program in Bioengineering, Berkeley, CA, USA
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28
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Quantitative microfluidic biomolecular analysis for systems biology and medicine. Anal Bioanal Chem 2013; 405:5743-58. [PMID: 23568613 DOI: 10.1007/s00216-013-6930-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Revised: 03/10/2013] [Accepted: 03/19/2013] [Indexed: 12/12/2022]
Abstract
In the postgenome era, biology and medicine are rapidly evolving towards quantitative and systems studies of complex biological systems. Emerging breakthroughs in microfluidic technologies and innovative applications are transforming systems biology by offering new capabilities to address the challenges in many areas, such as single-cell genomics, gene regulation networks, and pathology. In this review, we focus on recent progress in microfluidic technology from the perspective of its applications to promoting quantitative and systems biomolecular analysis in biology and medicine.
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29
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Hou C, Herr AE. Microfluidic integration of Western blotting is enabled by electrotransfer-assisted sodium dodecyl sulfate dilution. Analyst 2013; 138:158-63. [DOI: 10.1039/c2an36033k] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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30
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Abstract
Rapid, quantitative Western blotting is a long-sought bioanalytical goal in the life sciences. To this end, we describe a Western blotting assay conducted in a single glass microchannel under purely electronic control. The μWestern blot is comprised of multiple steps: sample enrichment, protein sizing, protein immobilization (blotting), and in situ antibody probing. To validate the microfluidic assay, we apply the μWestern blot to analyses of human sera (HIV immunoreactivity) and cell lysate (NFκB). Analytical performance advances are achieved, including: short durations of 10-60 min, multiplexed analyte detection, mass sensitivity at the femtogram level, high-sensitivity 50-pM detection limits, and quantitation capability over a 3.6-log dynamic range. Performance gains are attributed to favorable transport and reaction conditions on the microscale. The multistep assay design relies on a photopatternable (blue light) and photoreactive (UV light) polyacrylamide gel. This hydrophilic polymer constitutes both a separation matrix for protein sizing and, after brief UV exposure, a protein immobilization scaffold for subsequent antibody probing of immobilized protein bands. We observe protein capture efficiencies exceeding 75% under sizing conditions. This compact microfluidic design supports demonstration of a 48-plex μWestern blot in a standard microscope slide form factor. Taken together, the μWestern blot establishes a foundation for rapid, targeted proteomics by merging exceptional specificity with the throughput advantages of multiplexing, as is relevant to a broad range of biological inquiry.
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31
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Abstract
Rapid, quantitative Western blotting is a long-sought bioanalytical goal in the life sciences. To this end, we describe a Western blotting assay conducted in a single glass microchannel under purely electronic control. The μWestern blot is comprised of multiple steps: sample enrichment, protein sizing, protein immobilization (blotting), and in situ antibody probing. To validate the microfluidic assay, we apply the μWestern blot to analyses of human sera (HIV immunoreactivity) and cell lysate (NFκB). Analytical performance advances are achieved, including: short durations of 10-60 min, multiplexed analyte detection, mass sensitivity at the femtogram level, high-sensitivity 50-pM detection limits, and quantitation capability over a 3.6-log dynamic range. Performance gains are attributed to favorable transport and reaction conditions on the microscale. The multistep assay design relies on a photopatternable (blue light) and photoreactive (UV light) polyacrylamide gel. This hydrophilic polymer constitutes both a separation matrix for protein sizing and, after brief UV exposure, a protein immobilization scaffold for subsequent antibody probing of immobilized protein bands. We observe protein capture efficiencies exceeding 75% under sizing conditions. This compact microfluidic design supports demonstration of a 48-plex μWestern blot in a standard microscope slide form factor. Taken together, the μWestern blot establishes a foundation for rapid, targeted proteomics by merging exceptional specificity with the throughput advantages of multiplexing, as is relevant to a broad range of biological inquiry.
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32
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Abstract
Protein compositional data can address nutritional, packaging, origin/authenticity, processing history, safety and other quality questions. Such data has been time-consuming and expensive to generate until recently but “protein analysis on a chip” systems are now available that can analyze a complex food sample in a few minutes and do not require great protein analytical expertise. We review some of the main new approaches with examples of their application and discuss their advantages and disadvantages.
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Affiliation(s)
- Filomena Nazzaro
- Institute of Food Science, ISA-CNR, Via Roma 64, Avellino 83100, Italy; (F.F.); (A.D.L.); (R.C.)
- Author to whom correspondence should be addressed; ; Tel.:+39-0825299102; Fax: +39-0825781585
| | - Pierangelo Orlando
- Institute of Protein Biochemistry, IBP-CNR, Via P. Castellino 121, Napoli 80124, Italy;
| | - Florinda Fratianni
- Institute of Food Science, ISA-CNR, Via Roma 64, Avellino 83100, Italy; (F.F.); (A.D.L.); (R.C.)
| | - Aldo Di Luccia
- Institute of Food Science, ISA-CNR, Via Roma 64, Avellino 83100, Italy; (F.F.); (A.D.L.); (R.C.)
- Department of Food Science, University of Foggia, Via Napoli 25, Foggia 71100, Italy
| | - Raffaele Coppola
- Institute of Food Science, ISA-CNR, Via Roma 64, Avellino 83100, Italy; (F.F.); (A.D.L.); (R.C.)
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33
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Kim D, Karns K, Tia SQ, He M, Herr AE. Electrostatic Protein Immobilization Using Charged Polyacrylamide Gels and Cationic Detergent Microfluidic Western Blotting. Anal Chem 2012; 84:2533-40. [DOI: 10.1021/ac3000013] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Dohyun Kim
- Department of Bioengineering, University of California, Berkeley, 342 Stanley Hall,
Berkeley, California 94720, United States
| | - Kelly Karns
- The UC Berkeley − UCSF Graduate Program in Bioengineering, Berkeley,
California 94720, United States
| | - Samuel Q. Tia
- The UC Berkeley − UCSF Graduate Program in Bioengineering, Berkeley,
California 94720, United States
| | - Mei He
- Department of Bioengineering, University of California, Berkeley, 342 Stanley Hall,
Berkeley, California 94720, United States
| | - Amy E. Herr
- Department of Bioengineering, University of California, Berkeley, 342 Stanley Hall,
Berkeley, California 94720, United States
- The UC Berkeley − UCSF Graduate Program in Bioengineering, Berkeley,
California 94720, United States
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34
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Kovarik ML, Gach PC, Ornoff DM, Wang Y, Balowski J, Farrag L, Allbritton NL. Micro total analysis systems for cell biology and biochemical assays. Anal Chem 2012; 84:516-40. [PMID: 21967743 PMCID: PMC3264799 DOI: 10.1021/ac202611x] [Citation(s) in RCA: 180] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Michelle L. Kovarik
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Phillip C. Gach
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Douglas M. Ornoff
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599
- Department of Pharmacology, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Yuli Wang
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Joseph Balowski
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Lila Farrag
- School of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Nancy L. Allbritton
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599
- Department of Biomedical Engineering, University of North Carolina, Chapel Hill, NC 27599 and North Carolina State University, Raleigh, NC 27695
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35
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Affiliation(s)
- Joshua I. Cutler
- Department of Chemistry and International
Institute for Nanotechnology, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Evelyn Auyeung
- Department of Chemistry and International
Institute for Nanotechnology, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Chad A. Mirkin
- Department of Chemistry and International
Institute for Nanotechnology, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
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36
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He M, Novak J, Julian BA, Herr AE. Membrane-assisted online renaturation for automated microfluidic lectin blotting. J Am Chem Soc 2011; 133:19610-3. [PMID: 22070432 PMCID: PMC3267544 DOI: 10.1021/ja207963f] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Aberrant glycosylation plays a pivotal role in a diverse set of diseases, including cancer. A microfluidic lectin blotting platform is introduced to enable and expedite the identification of protein glycosylation based on protein size and affinity for specific lectins. The integrated multistage assay eliminates manual intervention steps required for slab-gel lectin blotting, increases total assay throughput, limits reagent and sample consumption, and is completed using one instrument. The assay comprises non-reducing sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) followed by online post-sizing SDS filtration and lectin-based affinity blotting. Important functionality is conferred through both device and assay advances that enable integration of nanoporous membranes flanking a central microchamber to create sub-nanoliter volume compartments that trap SDS-protein complexes and allow electrophoretic SDS removal with buffer exchange. Recapitulation of protein binding for lectin was optimized through quantitative assessment of SDS-treated green fluorescent protein. Immunoglobulin A1 aberrantly glycosylated with galactose-deficient O-glycans was probed in ~6 min using ~3 μL of sample. This new microfluidic lectin blotting platform provides a rapid and automated assay for the assessment of aberrant glycosylation.
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Affiliation(s)
- Mei He
- Bioengineering, University of California, Berkeley, California 94720, United States
| | - Jan Novak
- Departments of Microbiology and Medicine, University of Alabama, Birmingham, Alabama 35294, United States
| | - Bruce A. Julian
- Departments of Microbiology and Medicine, University of Alabama, Birmingham, Alabama 35294, United States
| | - Amy E. Herr
- Bioengineering, University of California, Berkeley, California 94720, United States
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