1
|
Cowell TW, Jing W, Noh H, Han HS. Drop-by-Drop Addition of Reagents to a Double Emulsion. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024:e2404121. [PMID: 39101620 DOI: 10.1002/smll.202404121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Revised: 07/08/2024] [Indexed: 08/06/2024]
Abstract
Developments in droplet microfluidics have facilitated an era of high-throughput, sensitive single-cell, or single-molecule measurements capable of tackling the heterogeneity present in biological systems. Relying on single emulsion (SE) compartments, droplet assays achieve absolute quantification of nucleic acids, massively parallel single-cell profiling, and more. Double emulsions (DEs) have seen recent interest for their potential to build upon SE techniques. DEs are compatible with flow cytometry enabling high-throughput multi-parameter drop screening and eliminate content mixing due to coalescence during lengthy workflows. Despite these strengths, DEs lack important technical functions that exist in SEs such as methods for adding reagents to droplets on demand. Consequently, DEs cannot be used for multistep workflows which has limited their adoption in assay development. Here, strategies to enable reagent addition and other active manipulations on DEs are reported by converting DE inputs to SEs on chip. After conversion, drops are manipulated using existing SE techniques, including reagent addition, before reforming a DE at the outlet. Device designs and operation conditions achieving drop-by-drop reagent addition to DEs are identified and used as part of a multi-step aptamer screening assay performed entirely in DE drops. This work enables the further development of multistep DE droplet assays.
Collapse
Affiliation(s)
- Thomas W Cowell
- Department of Chemistry, University of Illinois at Urbana-Champaign, 505 South Matthews Ave, Urbana, IL, 61801, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W Gregory Dr., Urbana, IL, 61801, USA
| | - Wenyang Jing
- Department of Biophysics, University of Illinois at Urbana-Champaign, 600 South Matthews Ave, Urbana, IL, 61801, USA
| | - Heewon Noh
- Department of Chemistry, University of Illinois at Urbana-Champaign, 505 South Matthews Ave, Urbana, IL, 61801, USA
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, 600 South Matthews Ave, Urbana, IL, 61801, USA
| | - Hee-Sun Han
- Department of Chemistry, University of Illinois at Urbana-Champaign, 505 South Matthews Ave, Urbana, IL, 61801, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W Gregory Dr., Urbana, IL, 61801, USA
- Department of Biophysics, University of Illinois at Urbana-Champaign, 600 South Matthews Ave, Urbana, IL, 61801, USA
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, 600 South Matthews Ave, Urbana, IL, 61801, USA
| |
Collapse
|
2
|
Stucki A, Vallapurackal J, Ward TR, Dittrich PS. Droplet Microfluidics and Directed Evolution of Enzymes: An Intertwined Journey. Angew Chem Int Ed Engl 2021; 60:24368-24387. [PMID: 33539653 PMCID: PMC8596820 DOI: 10.1002/anie.202016154] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Indexed: 12/12/2022]
Abstract
Evolution is essential to the generation of complexity and ultimately life. It relies on the propagation of the properties, traits, and characteristics that allow an organism to survive in a challenging environment. It is evolution that shaped our world over about four billion years by slow and iterative adaptation. While natural evolution based on selection is slow and gradual, directed evolution allows the fast and streamlined optimization of a phenotype under selective conditions. The potential of directed evolution for the discovery and optimization of enzymes is mostly limited by the throughput of the tools and methods available for screening. Over the past twenty years, versatile tools based on droplet microfluidics have been developed to address the need for higher throughput. In this Review, we provide a chronological overview of the intertwined development of microfluidics droplet-based compartmentalization methods and in vivo directed evolution of enzymes.
Collapse
Affiliation(s)
- Ariane Stucki
- Department of Biosystems Science and EngineeringETH ZurichMattenstrasse 26CH-4058BaselSwitzerland
- National Competence Center in Research (NCCR)Molecular Systems EngineeringBaselSwitzerland
| | - Jaicy Vallapurackal
- Department of ChemistryUniversity of BaselMattenstrasse 24aCH-4058BaselSwitzerland
- National Competence Center in Research (NCCR)Molecular Systems EngineeringBaselSwitzerland
| | - Thomas R. Ward
- Department of ChemistryUniversity of BaselMattenstrasse 24aCH-4058BaselSwitzerland
- National Competence Center in Research (NCCR)Molecular Systems EngineeringBaselSwitzerland
| | - Petra S. Dittrich
- Department of Biosystems Science and EngineeringETH ZurichMattenstrasse 26CH-4058BaselSwitzerland
- National Competence Center in Research (NCCR)Molecular Systems EngineeringBaselSwitzerland
| |
Collapse
|
3
|
Stucki A, Jusková P, Nuti N, Schmitt S, Dittrich PS. Synchronized Reagent Delivery in Double Emulsions for Triggering Chemical Reactions and Gene Expression. SMALL METHODS 2021; 5:e2100331. [PMID: 34927870 DOI: 10.1002/smtd.202100331] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 05/21/2021] [Indexed: 06/14/2023]
Abstract
Microfluidic methods for the formation of single and double emulsion (DE) droplets allow for the encapsulation and isolation of reactants inside nanoliter compartments. Such methods have greatly enhanced the toolbox for high-throughput screening for cell or enzyme engineering and drug discovery. However, remaining challenges in the supply of reagents into these enclosed compartments limit the applicability of droplet microfluidics. Here, a strategy is introduced for on-demand delivery of reactants in DEs. Lipid vesicles are used as reactant carriers, which are co-encapsulated in double emulsions and release their cargo upon addition of an external trigger, here the anionic surfactant sodium dodecyl sulfate (SDS). The reagent present inside the lipid vesicles stays isolated from the remaining content of the DE vessel until SDS enters the DE lumen and solubilizes the vesicles' lipid bilayer. The versatility of the method is demonstrated with two critical applications chosen as representative assays for high-throughput screening: the induction of gene expression in bacteria and the initiation of an enzymatic reaction. This method not only allows for the release of the lipid vesicle content inside DEs to be synchronized for all DEs but also for the release to be triggered at any desired time.
Collapse
Affiliation(s)
- Ariane Stucki
- Department of Biosystems Science and Engineering, Bioanalytics Group, ETH Zürich, Mattenstrasse 26, Basel, CH-4058, Switzerland
- NCCR Molecular Systems Engineering, BPR 1095, Mattenstrasse 24a, Basel, CH-4058, Switzerland
| | - Petra Jusková
- Department of Biosystems Science and Engineering, Bioanalytics Group, ETH Zürich, Mattenstrasse 26, Basel, CH-4058, Switzerland
| | - Nicola Nuti
- Department of Biosystems Science and Engineering, Bioanalytics Group, ETH Zürich, Mattenstrasse 26, Basel, CH-4058, Switzerland
| | - Steven Schmitt
- Department of Biosystems Science and Engineering, Bioprocess Laboratory, ETH Zürich, Mattenstrasse 26, Basel, CH-4058, Switzerland
| | - Petra S Dittrich
- Department of Biosystems Science and Engineering, Bioanalytics Group, ETH Zürich, Mattenstrasse 26, Basel, CH-4058, Switzerland
- NCCR Molecular Systems Engineering, BPR 1095, Mattenstrasse 24a, Basel, CH-4058, Switzerland
| |
Collapse
|
4
|
Stucki A, Vallapurackal J, Ward TR, Dittrich PS. Droplet Microfluidics and Directed Evolution of Enzymes: An Intertwined Journey. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202016154] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Ariane Stucki
- Department of Biosystems Science and Engineering ETH Zurich Mattenstrasse 26 CH-4058 Basel Switzerland
- National Competence Center in Research (NCCR) Molecular Systems Engineering Basel Switzerland
| | - Jaicy Vallapurackal
- Department of Chemistry University of Basel Mattenstrasse 24a CH-4058 Basel Switzerland
- National Competence Center in Research (NCCR) Molecular Systems Engineering Basel Switzerland
| | - Thomas R. Ward
- Department of Chemistry University of Basel Mattenstrasse 24a CH-4058 Basel Switzerland
- National Competence Center in Research (NCCR) Molecular Systems Engineering Basel Switzerland
| | - Petra S. Dittrich
- Department of Biosystems Science and Engineering ETH Zurich Mattenstrasse 26 CH-4058 Basel Switzerland
- National Competence Center in Research (NCCR) Molecular Systems Engineering Basel Switzerland
| |
Collapse
|
5
|
Zhang H, Guzman AR, Wippold JA, Li Y, Dai J, Huang C, Han A. An ultra high-efficiency droplet microfluidics platform using automatically synchronized droplet pairing and merging. LAB ON A CHIP 2020; 20:3948-3959. [PMID: 32935710 DOI: 10.1039/d0lc00757a] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Droplet microfluidics systems hold great promise in their ability to conduct high-throughput assays for a broad range of life science applications. Despite their promise in the field and capability to conduct complex liquid handling steps, currently, most droplet microfluidic systems used for real assays utilize only a few droplet manipulation steps connected in series, and are often not integrated together on a single chip or platform. This is due to the fact that linking multiple sequential droplet functions within a single chip to operate at high efficiency over long periods of time remains technically challenging. Considering sequential manipulation is often required to conduct high-throughput screening assays on large cellular and molecular libraries, advancements in sequential operation and integration are required to advance the field. This current limitation greatly reduces the type of assays that can be realized in a high-throughput droplet format and becomes more prevalent in large library screening applications. Here we present an integrated multi-layer droplet microfluidic platform that can handle large numbers of droplets with high efficiency and minimum error. The platform combines two-photon photolithography-fabricated curved microstructures that allow high-efficiency (99.9%) re-flow of droplets and a unique droplet cleaving that automatically synchronizes paired droplets enabling high-efficiency (99.9%) downstream merging. We demonstrate that this method is applicable to a broad range of droplet sizes, including relatively large droplet sizes (hundreds of micrometers in diameter) that are typically more difficult to manipulate with high efficiency, yet are required in many cell assay applications requiring large organisms or multiple incubation steps. The utility of this highly efficient integrated droplet microfluidic platform was demonstrated by conducting a mock antibiotic screening assay against a bacterial pathogen. The approach and system presented here provides new avenues for the realization of ultra-high-efficiency multi-step droplet microfluidic systems with minimal error.
Collapse
Affiliation(s)
- Han Zhang
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas 77843, USA.
| | | | | | | | | | | | | |
Collapse
|
6
|
Payne EM, Holland-Moritz DA, Sun S, Kennedy RT. High-throughput screening by droplet microfluidics: perspective into key challenges and future prospects. LAB ON A CHIP 2020; 20:2247-2262. [PMID: 32500896 DOI: 10.1039/d0lc00347f] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
In two decades of development, impressive strides have been made for automating basic laboratory operations in droplet-based microfluidics, allowing the emergence of a new form of high-throughput screening and experimentation in nanoliter to femtoliter volumes. Despite advancements in droplet storage, manipulation, and analysis, the field has not yet been widely adapted for many high-throughput screening (HTS) applications. Broad adoption and commercial development of these techniques require robust implementation of strategies for the stable storage, chemical containment, generation of libraries, sample tracking, and chemical analysis of these small samples. We discuss these challenges for implementing droplet HTS and highlight key strategies that have begun to address these concerns. Recent advances in the field leave us optimistic about the future prospects of this rapidly developing technology.
Collapse
Affiliation(s)
- Emory M Payne
- Department of Chemistry, University of Michigan, Ann Arbor, MI, USA.
| | | | | | | |
Collapse
|
7
|
Brower KK, Carswell-Crumpton C, Klemm S, Cruz B, Kim G, Calhoun SGK, Nichols L, Fordyce PM. Double emulsion flow cytometry with high-throughput single droplet isolation and nucleic acid recovery. LAB ON A CHIP 2020; 20:2062-2074. [PMID: 32417874 PMCID: PMC7670282 DOI: 10.1039/d0lc00261e] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Droplet microfluidics has made large impacts in diverse areas such as enzyme evolution, chemical product screening, polymer engineering, and single-cell analysis. However, while droplet reactions have become increasingly sophisticated, phenotyping droplets by a fluorescent signal and sorting them to isolate individual variants-of-interest at high-throughput remains challenging. Here, we present sdDE-FACS (s[combining low line]ingle d[combining low line]roplet D[combining low line]ouble E[combining low line]mulsion-FACS), a new method that uses a standard flow cytometer to phenotype, select, and isolate individual double emulsion droplets of interest. Using a 130 μm nozzle at high sort frequency (12-14 kHz), we demonstrate detection of droplet fluorescence signals with a dynamic range spanning 5 orders of magnitude and robust post-sort recovery of intact double emulsion (DE) droplets using 2 commercially-available FACS instruments. We report the first demonstration of single double emulsion droplet isolation with post-sort recovery efficiencies >70%, equivalent to the capabilities of single-cell FACS. Finally, we establish complete downstream recovery of nucleic acids from single, sorted double emulsion droplets via qPCR with little to no cross-contamination. sdDE-FACS marries the full power of droplet microfluidics with flow cytometry to enable a variety of new droplet assays, including rare variant isolation and multiparameter single-cell analysis.
Collapse
Affiliation(s)
- Kara K Brower
- Department of Bioengineering, Stanford University, Stanford, California, USA.
| | | | | | | | | | | | | | | |
Collapse
|
8
|
Droplet Microfluidics-Enabled High-Throughput Screening for Protein Engineering. MICROMACHINES 2019; 10:mi10110734. [PMID: 31671786 PMCID: PMC6915371 DOI: 10.3390/mi10110734] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Revised: 10/22/2019] [Accepted: 10/26/2019] [Indexed: 12/19/2022]
Abstract
Protein engineering—the process of developing useful or valuable proteins—has successfully created a wide range of proteins tailored to specific agricultural, industrial, and biomedical applications. Protein engineering may rely on rational techniques informed by structural models, phylogenic information, or computational methods or it may rely upon random techniques such as chemical mutation, DNA shuffling, error prone polymerase chain reaction (PCR), etc. The increasing capabilities of rational protein design coupled to the rapid production of large variant libraries have seriously challenged the capacity of traditional screening and selection techniques. Similarly, random approaches based on directed evolution, which relies on the Darwinian principles of mutation and selection to steer proteins toward desired traits, also requires the screening of very large libraries of mutants to be truly effective. For either rational or random approaches, the highest possible screening throughput facilitates efficient protein engineering strategies. In the last decade, high-throughput screening (HTS) for protein engineering has been leveraging the emerging technologies of droplet microfluidics. Droplet microfluidics, featuring controlled formation and manipulation of nano- to femtoliter droplets of one fluid phase in another, has presented a new paradigm for screening, providing increased throughput, reduced reagent volume, and scalability. We review here the recent droplet microfluidics-based HTS systems developed for protein engineering, particularly directed evolution. The current review can also serve as a tutorial guide for protein engineers and molecular biologists who need a droplet microfluidics-based HTS system for their specific applications but may not have prior knowledge about microfluidics. In the end, several challenges and opportunities are identified to motivate the continued innovation of microfluidics with implications for protein engineering.
Collapse
|
9
|
Azarmanesh M, Bawazeer S, Mohamad AA, Sanati-Nezhad A. Rapid and Highly Controlled Generation of Monodisperse Multiple Emulsions via a One-Step Hybrid Microfluidic Device. Sci Rep 2019; 9:12694. [PMID: 31481702 PMCID: PMC6722102 DOI: 10.1038/s41598-019-49136-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 08/20/2019] [Indexed: 02/07/2023] Open
Abstract
Multiple Emulsions (MEs) contain a drop laden with many micro-droplets. A single-step microfluidic-based synthesis process of MEs is presented to provide a rapid and controlled generation of monodisperse MEs. The design relies on the interaction of three immiscible fluids with each other in subsequent droplet formation steps to generate monodisperse ME constructs. The design is within a microchannel consists of two compartments of cross-junction and T-junction. The high shear stress at the cross-junction creates a stagnation point that splits the first immiscible phase to four jet streams each of which are sprayed to micrometer droplets surrounded by the second phase. The resulted structure is then supported by the third phase at the T-junction to generate and transport MEs. The ME formation within microfluidics is numerically simulated and the effects of several key parameters on properties of MEs are investigated. The dimensionless modeling of ME formation enables to change only one parameter at the time and analyze the sensitivity of the system to each parameter. The results demonstrate the capability of highly controlled and high-throughput MEs formation in a one-step synthesis process. The consecutive MEs are monodisperse in size which open avenues for the generation of controlled MEs for different applications.
Collapse
Affiliation(s)
- Milad Azarmanesh
- Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
| | - Saleh Bawazeer
- Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
| | - Abdulmajeed A Mohamad
- Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, Alberta, T2N 1N4, Canada.
| | - Amir Sanati-Nezhad
- Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, Alberta, T2N 1N4, Canada. .,Center for Bioengineering Research and Education, Biomedical Engineering Program, University of Calgary, Calgary, Alberta, T2N 1N4, Canada.
| |
Collapse
|
10
|
|
11
|
Noh YM, Jin SH, Jeong SG, Kim NY, Rho C, Lee CS. Increase in Voltage Efficiency of Picoinjection using Microfluidic Picoinjector Combined Faraday Moat with Silver Nanoparticles Electrode. KOREAN CHEMICAL ENGINEERING RESEARCH 2015. [DOI: 10.9713/kcer.2015.53.4.472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
12
|
Sciambi A, Abate AR. Generating electric fields in PDMS microfluidic devices with salt water electrodes. LAB ON A CHIP 2014; 14:2605-9. [PMID: 24671446 PMCID: PMC4079735 DOI: 10.1039/c4lc00078a] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Droplet merging and sorting in microfluidic devices usually rely on electric fields generated by solid metal electrodes. We show that simpler and more reliable salt water electrodes, despite their lower conductivity, can perform the same droplet manipulations at the same voltages.
Collapse
Affiliation(s)
- Adam Sciambi
- Department of Bioengineering and Therapeutic Sciences, California Institute for Quantitative Biosciences, University of California, San Francisco, California, USA.
| | | |
Collapse
|