Name: high throughput single-cell and multiple-cell micro-encapsulation
Uploaded: 2012-06-15T12:00:00
Description: Watch this Scientific Journal Video about High Throughput Single-cell and Multiple-cell Micro-encapsulation at JoVE.com

Wir danken RainDance Technologies für die Probe von PFPE-PEG-Tensid in dieser Studie verwendeten, und wir danken den BioMEMS Resource Center (Mehmet Toner, Regisseur) für die Silizium-Wafer verwendet werden, um Schimmel PDMS-Kanal Repliken zu erstellen.

Die Protokolle in diesem Abschnitt beschreiben die Materialien und Ausrüstungen, die speziell auf die experimentellen Ergebnisse präsentiert bekommen genutzt. Beachten Sie, dass andere Anbieter für Chemikalien und Ausrüstung verwendet werden kann. 1. Bauelementherstellung und Softlithographie Standard-Soft-Lithographie-Techniken, 21 von denen einige in früheren JOVE Artikel wurden oft vorgestellten wurden 22 für die Erstellung von Polydi...

<ol>
	<li>Zagnoni, M., Lain, G. L. e., Cooper, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrocoalescence+mechanisms+of+microdroplets+using+localized+electric+fields+in+microfluidic+channels.">Electrocoalescence mechanisms of microdroplets using localized electric fields in microfluidic channels.</a> Langmuir : the ACS journal of surfaces and colloids. 26, 14443-14449 (2010).</li><li>Niu, X. Z., Gielen, F., Edel, J. B., deMello, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+microdroplet+dilutor+for+high-throughput+screening.">A microdroplet dilutor for high-throughput screening.</a> Nat. Chem. 3, 437-442 (2011).</li><li>Vincent, M. E., Liu, W., Haney, E. B., Ismagilov, R. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microfluidic+stochastic+confinement+enhances+analysis+of+rare+cells+by+isolating+cells+and+creating+high+density+environments+for+control+of+diffusible+signals.">Microfluidic stochastic confinement enhances analysis of rare cells by isolating cells and creating high density environments for control of diffusible signals.</a> Chemical Society reviews. 39, 974-984 (2010).</li><li>Huebner, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+detection+of+protein+expression+in+single+cells+using+droplet+microfluidics.">Quantitative detection of protein expression in single cells using droplet microfluidics.</a> Chemical communications. , 1218-1220 (2007).</li><li>Love, J. C., Ronan, J. L., Grotenbreg, G. M., van der Veen, A. G., Ploegh, H. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+microengraving+method+for+rapid+selection+of+single+cells+producing+antigen-specific+antibodies.">A microengraving method for rapid selection of single cells producing antigen-specific antibodies.</a> Nature biotechnology. 24, 703-707 (2006).</li><li>Bradshaw, E. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Concurrent+detection+of+secreted+products+from+human+lymphocytes+by+microengraving:+Cytokines+and+antigen-reactive+antibodies.">Concurrent detection of secreted products from human lymphocytes by microengraving: Cytokines and antigen-reactive antibodies.</a> Clin. Immunol. 129, 10-18 (2008).</li><li>Liu, W. S., Kim, H. J., Lucchetta, E. M., Du, W. B., Ismagilov, R. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation,+incubation,+and+parallel+functional+testing+and+identification+by+FISH+of+rare+microbial+single-copy+cells+from+multi-species+mixtures+using+the+combination+of+chemistrode+and+stochastic+confinement.">Isolation, incubation, and parallel functional testing and identification by FISH of rare microbial single-copy cells from multi-species mixtures using the combination of chemistrode and stochastic confinement.</a> Lab on a chip. 9, 2153-2162 (2009).</li><li>Boedicker, J. Q., Li, L., Kline, T. R., Ismagilov, R. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detecting+bacteria+and+determining+their+susceptibility+to+antibiotics+by+stochastic+confinement+in+nanoliter+droplets+using+plug-based+microfluidics.">Detecting bacteria and determining their susceptibility to antibiotics by stochastic confinement in nanoliter droplets using plug-based microfluidics.</a> Lab on a chip. 8, 1265-1272 (2008).</li><li>Koster, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Drop-based+microfluidic+devices+for+encapsulation+of+single+cells.">Drop-based microfluidic devices for encapsulation of single cells.</a> Lab on a chip. 8, 1110-1115 (2008).</li><li>Kelly, R. T., Page, J. S., Marginean, I., Tang, K., Smith, R. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dilution-free+analysis+from+picoliter+droplets+by+nano-electrospray+ionization+mass+spectrometry.">Dilution-free analysis from picoliter droplets by nano-electrospray ionization mass spectrometry.</a> Angew Chem. Int. Ed. Engl. 48, 6832-6835 (2009).</li><li>Hong, J., deMello, A. J., Jayasinghe, S. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bio-electrospraying+and+droplet-based+microfluidics:+control+of+cell+numbers+within+living+residues.">Bio-electrospraying and droplet-based microfluidics: control of cell numbers within living residues.</a> Biomedical materials. 5, 21001 (2010).</li><li>Edd, J. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Controlled+encapsulation+of+single-cells+into+monodisperse+picolitre+drops.">Controlled encapsulation of single-cells into monodisperse picolitre drops.</a> Lab on a chip. 8, 1262-1264 (2008).</li><li>Anna, S. L., Bontoux, N., Stone, H. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Formation+of+dispersions+using+"flow+focusing"+in+microchannels.">Formation of dispersions using "flow focusing" in microchannels.</a> Applied Physics Letters. 82, 364 (2003).</li><li>Utada, A., Fernandez-Nieves, A., Stone, H., Weitz, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dripping+to+Jetting+Transitions+in+Coflowing+Liquid+Streams.">Dripping to Jetting Transitions in Coflowing Liquid Streams.</a> Physical Review Letters. 99, (2007).</li><li>Chabert, M., Viovy, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microfluidic+high-throughput+encapsulation+and+hydrodynamic+self-sorting+of+single+cells.">Microfluidic high-throughput encapsulation and hydrodynamic self-sorting of single cells.</a> Proceedings of the National Academy of Sciences of the United States of America. 105, 3191-3196 (2008).</li><li>Segr&#237;, G., Silberberg, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Radial+Particle+Displacements+in+Poiseuille+Flow+of+Suspensions.">Radial Particle Displacements in Poiseuille Flow of Suspensions.</a> Nature. 189, 209-210 (1961).</li><li>Carlo, D. D. i. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inertial+microfluidics.">Inertial microfluidics.</a> Lab on a chip. 9, 3038-3046 (2009).</li><li>Carlo, D. D. i., Edd, J., Humphry, K., Stone, H., Toner, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Particle+Segregation+and+Dynamics+in+Confined+Flows.">Particle Segregation and Dynamics in Confined Flows.</a> Physical Review Letters. 102, (2009).</li><li>Humphry, K. J., Kulkarni, P. M., Weitz, D. A., Morris, J. F., Stone, H. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Axial+and+lateral+particle+ordering+in+finite+Reynolds+number+channel+flows.">Axial and lateral particle ordering in finite Reynolds number channel flows.</a> Physics of Fluids. 22, 081703 (2010).</li><li>Lee, W., Amini, H., Stone, H. A., Carlo, D. D. i. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dynamic+self-assembly+and+control+of+microfluidic+particle+crystals.">Dynamic self-assembly and control of microfluidic particle crystals.</a> Proceedings of the National Academy of Sciences of the United States of America. 107, 22413 (2010).</li><li>Duffy, D. C., McDonald, J. C., Schueller, O. J. A., Whitesides, G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+prototyping+of+microfluidic+systems+in+poly(dimethylsiloxane.">Rapid prototyping of microfluidic systems in poly(dimethylsiloxane.</a> Anal. Chem. 70, 4974-4984 (1998).</li><li>Kotz, K., Cheng, X., Toner, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=PDMS+Device+Fabrication+and+Surface+Modification.">PDMS Device Fabrication and Surface Modification.</a> J. Vis. Exp. (8), e319 (2007).</li><li>Haubert, K., Drier, T., Beebe, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=PDMS+bonding+by+means+of+a+portable,+low-cost+corona+system.">PDMS bonding by means of a portable, low-cost corona system.</a> Lab on a chip. 6, 1548-1549 (2006).</li><li>Hatch, A. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=1-Million+droplet+array+with+wide-field+fluorescence+imaging+for+digital+PCR.">1-Million droplet array with wide-field fluorescence imaging for digital PCR.</a> Lab on a chip. , 3838-3845 (2011).</li><li>Holtze, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biocompatible+surfactants+for+water-in-fluorocarbon+emulsions.">Biocompatible surfactants for water-in-fluorocarbon emulsions.</a> Lab on a chip. 8, 1632-1639 (2008).</li><li>Garstecki, P., Stone, H., Whitesides, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanism+for+Flow-Rate+Controlled+Breakup+in+Confined+Geometries:+A+Route+to+Monodisperse+Emulsions.">Mechanism for Flow-Rate Controlled Breakup in Confined Geometries: A Route to Monodisperse Emulsions.</a> Physical Review Letters. 94, (2005).</li><li>Garstecki, P., Fuerstman, M. J., Stone, H. A., Whitesides, G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Formation+of+droplets+and+bubbles+in+a+microfluidic+T-junction-scaling+and+mechanism+of+break-up.">Formation of droplets and bubbles in a microfluidic T-junction-scaling and mechanism of break-up.</a> Lab on a chip. 6, 437-446 (2006).</li><li>Nie, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Emulsification+in+a+microfluidic+flow-focusing+device:+effect+of+the+viscosities+of+the+liquids.">Emulsification in a microfluidic flow-focusing device: effect of the viscosities of the liquids.</a> Microfluidics and Nanofluidics. , (2008).</li><li>Holt, D. J., Payne, R. J., Chow, W. Y., Abell, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluorosurfactants+for+microdroplets:+interfacial+tension+analysis.">Fluorosurfactants for microdroplets: interfacial tension analysis.</a> Journal of colloid and interface science. 350, 205-211 (2010).</li><li>Holt, D. J., Payne, R. J., Abell, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+of+novel+fluorous+surfactants+for+microdroplet+stabilisation+in+fluorous+oil+streams.">Synthesis of novel fluorous surfactants for microdroplet stabilisation in fluorous oil streams.</a> Journal of Fluorine Chemistry. 131, 398-407 (2010).</li><li>Hatch, A. C., Fisher, J. S., Pentoney, S. L., Yang, D. L., Lee, A. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tunable+3D+droplet+self-assembly+for+ultra-high-density+digital+micro-reactor+arrays.">Tunable 3D droplet self-assembly for ultra-high-density digital micro-reactor arrays.</a> Lab on a chip. 11, 2509-2517 (2011).</li><li>Baret, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surfactants+in+droplet-based+microfluidics.">Surfactants in droplet-based microfluidics.</a> Lab on a chip. 12, 422-433 (2012).</li></ol>

Trotz der relativ hohen Grad der Bestellung werden nicht alle Tropfen enthalten die richtige Anzahl von Partikeln oder Zellen. Verkapselungseffizienz kann als die Anzahl von Zellen oder Partikeln, die in Tropfen mit der gewünschten Belegung durch die Gesamtzahl unterteilt eingekapselt geworden berechnet werden. Diese Rohdaten können entweder von einem automatisierten High-Speed-Video-Algorithmus oder aus einer Stichprobe von Imaging gesammelt Emulsion erhalten werden. Dies kann zu der Fraktion von Teilchen P ...

<table border="1"><tbody><tr><td> Name des Reagenzes </td><td> Firma </td><td> Katalog-Nummer </td><td> Kommentare </td></tr><tr><td> AutoCAD </td><td> AutoDesk </td><td></td><td></td></tr><tr><td> Transparenz-Maske </td><td> Fineline Imaging Inc. </td><td></td><td></td></tr><tr><td> SU-8 Fotolack </td><td> MicroChem </td><td> 2050 </td><td></td></tr><tr><td> Dektak Profilometer </td><td> Veeco </td><td></td><td></td></tr><tr><td> Petrischale </td><td> BD Falcon </td><td> 351058 </td><td></td></tr><tr><td> PDMS-Silikon-Elastomer-Kit </td><td> Dow Corning Corp </td><td> Sylgard 184, Werkstoff-Nummer (240) 4019862 </td><td></td></tr><tr><td> Vakuumexsikkator </td><td> Jencons </td><td> 250-030 </td><td></td></tr><tr><td> Vakuumpumpe </td><td> Alcatel Vacuum Technology </td><td> 2010 C2 </td><td></td></tr><tr><td> Vakuumregler </td><td> Cole-Parmer </td><td> EW-00910-10 </td><td></td></tr><tr><td> Backofen </td><td> Thermo Scientific </td><td> Lindberg Blue M, OV800F </td><td></td></tr><tr><td> Biopsiestanze, 0,75 mm </td><td> Harris </td><td> Uni-Core-15072 </td><td></td></tr><tr><td> Labor Corona Anlage </td><td> Electro-Technic Products Inc. </td><td> BD-20AC, SKU 12051A </td><td></td></tr><tr><td> Glas-Folien </td><td> Gold Seal </td><td> 3010 </td><td></td></tr><tr><td> Aquapel </td><td> PPG Industries </td><td></td><td> Alternative Strategie </td></tr><tr><td> Polystyrol-Mikrokügelchen, um 9,9 </td><td> Thermo </td><td> G1000 </td><td></td></tr> &lt;tr&gt; <td> Optiprep </td><td> Sigma-Aldrich </td><td> D1556 </td><td> Nicht nachgewiesen </td></tr><tr><td> Luer-Lok Spritzen </td><td> BD </td><td> 1 ml: 309628 3 ml: 309585 </td><td></td></tr><tr><td> FC-40 Fluorkohlenstofföl </td><td> 3M Inc. </td><td> Sigma Aldrich, F9755 </td><td></td></tr><tr><td> PFPE-PEG Fluortensid </td><td> RainDance Technologies </td><td></td><td></td></tr><tr><td> Leichtes Mineralöl </td><td> PTI Process Chemicals </td><td> 08042-47-5 </td><td> Alternative Strategie </td></tr><tr><td> Mineral-Öl-Tensid </td><td> Evonik Goldschmidt GmbH </td><td> Abil EM 90 </td><td> Alternative Strategie </td></tr><tr><td> Tygon Schlauch aus PVC </td><td> Kleinteile </td><td> TGY-010 </td><td></td></tr><tr><td> 30-Gauge-Luer-Lok Spritzennadel, 1/2 &quot; </td><td> Kleinteile </td><td> NE-301PL-C </td><td></td></tr><tr><td> Inverses Mikroskop </td><td> Carl Zeiss Imaging </td><td> Axio Observer.Z1 </td><td></td></tr><tr><td> High Speed ​​Kamera </td><td> Vision Research </td><td> Phantom V310 </td><td></td></tr><tr><td> Spritzenpumpen (2) </td><td> Chemyx Inc. </td><td> Nexus 3000 </td><td></td></tr><tr><td> Silikonöl </td><td> Dow Corning </td><td> 200 Fluid, 10 cSt </td><td> Optional für Storage-Emulsion </td></tr></tbody></table>

high throughput single-cell and multiple-cell micro-encapsulation

Microfluidic encapsulation methods have been previously utilized to capture cells in picoliter-scale aqueous, monodisperse drops, providing confinement from a bulk fluid environment with applications in high throughput screening, cytometry, and mass spectrometry. We describe a method to not only encapsulate single cells, but to repeatedly capture a set number of cells (here we demonstrate one- and two-cell encapsulation) to study both isolation and the interactions between cells in groups of controlled sizes. By combining drop generation techniques with cell and particle ordering, we demonstrate controlled encapsulation of cell-sized particles for efficient, continuous encapsulation. Using an aqueous particle suspension and immiscible fluorocarbon oil, we generate aqueous drops in oil with a flow focusing nozzle. The aqueous flow rate is sufficiently high to create ordering of particles which reach the nozzle at integer multiple frequencies of the drop generation frequency, encapsulating a controlled number of cells in each drop. For representative results, 9.9 &mu;m polystyrene particles are used as cell surrogates. This study shows a single-particle encapsulation efficiency Pk=1 of 83.7% and a double-particle encapsulation efficiency Pk=2 of 79.5% as compared to their respective Poisson efficiencies of 39.3% and 33.3%, respectively. The effect of consistent cell and particle concentration is demonstrated to be of major importance for efficient encapsulation, and dripping to jetting transitions are also addressed. 
Introduction 
Continuous media aqueous cell suspensions share a common fluid environment which allows cells to interact in parallel and also homogenizes the effects of specific cells in measurements from the media. High-throughput encapsulation of cells into picoliter-scale drops confines the samples to protect drops from cross-contamination, enable a measure of cellular diversity within samples, prevent dilution of reagents and expressed biomarkers, and amplify signals from bioreactor products. Drops also provide the ability to re-merge drops into larger aqueous samples or with other drops for intercellular signaling studies.1,2 The reduction in dilution implies stronger detection signals for higher accuracy measurements as well as the ability to reduce potentially costly sample and reagent volumes.3 Encapsulation of cells in drops has been utilized to improve detection of protein expression,4 antibodies,5,6 enzymes,7 and metabolic activity8 for high throughput screening, and could be used to improve high throughput cytometry.9 Additional studies present applications in bio-electrospraying of cell containing drops for mass spectrometry10 and targeted surface cell coatings.11 Some applications, however, have been limited by the lack of ability to control the number of cells encapsulated in drops. Here we present a method of ordered encapsulation12 which increases the demonstrated encapsulation efficiencies for one and two cells and may be extrapolated for encapsulation of a larger number of cells.
To achieve monodisperse drop generation, microfluidic "flow focusing" enables the creation of controllable-size drops of one fluid (an aqueous cell mixture) within another (a continuous oil phase) by using a nozzle at which the streams converge.13 For a given nozzle geometry, the drop generation frequency f and drop size can be altered by adjusting oil and aqueous flow rates Qoil and Qaq. As the flow rates increase, the flows may transition from drop generation to unstable jetting of aqueous fluid from the nozzle.14 
When the aqueous solution contains suspended particles, particles become encapsulated and isolated from one another at the nozzle. For drop generation using a randomly distributed aqueous cell suspension, the average fraction of drops Dk containing k cells is dictated by Poisson statistics, where Dk = &lambda;k exp(-&lambda;)/(k!) and &lambda; is the average number of cells per drop. The fraction of cells which end up in the "correctly" encapsulated drops is calculated using Pk = (k x Dk)/&Sigma;(k' x Dk'). The subtle difference between the two metrics is that Dk relates to the utilization of aqueous fluid and the amount of drop sorting that must be completed following encapsulation, and Pk relates to the utilization of the cell sample. As an example, one could use a dilute cell suspension (low &lambda;) to encapsulate drops where most drops containing cells would contain just one cell. While the efficiency metric Pk would be high, the majority of drops would be empty (low Dk), thus requiring a sorting mechanism to remove empty drops, also reducing throughput.15
Combining drop generation with inertial ordering provides the ability to encapsulate drops with more predictable numbers of cells per drop and higher throughputs than random encapsulation. Inertial focusing was first discovered by Segre and Silberberg16 and refers to the tendency of finite-sized particles to migrate to lateral equilibrium positions in channel flow. Inertial ordering refers to the tendency of the particles and cells to passively organize into equally spaced, staggered, constant velocity trains. Both focusing and ordering require sufficiently high flow rates (high Reynolds number) and particle sizes (high Particle Reynolds number).17,18 Here, the Reynolds number Re =uDh/&nu; and particle Reynolds number Rep =Re(a/Dh)2, where u is a characteristic flow velocity, Dh [=2wh/(w+h)] is the hydraulic diameter, &nu; is the kinematic viscosity, a is the particle diameter, w is the channel width, and h is the channel height. Empirically, the length required to achieve fully ordered trains decreases as Re and Rep increase. Note that the high Re and Rep requirements (for this study on the order of 5 and 0.5, respectively) may conflict with the need to keep aqueous flow rates low to avoid jetting at the drop generation nozzle. Additionally, high flow rates lead to higher shear stresses on cells, which are not addressed in this protocol. The previous ordered encapsulation study demonstrated that over 90% of singly encapsulated HL60 cells under similar flow conditions to those in this study maintained cell membrane integrity.12 However, the effect of the magnitude and time scales of shear stresses will need to be carefully considered when extrapolating to different cell types and flow parameters. The overlapping of the cell ordering, drop generation, and cell viability aqueous flow rate constraints provides an ideal operational regime for controlled encapsulation of single and multiple cells.
Because very few studies address inter-particle train spacing,19,20 determining the spacing is most easily done empirically and will depend on channel geometry, flow rate, particle size, and particle concentration. Nonetheless, the equal lateral spacing between trains implies that cells arrive at predictable, consistent time intervals. When drop generation occurs at the same rate at which ordered cells arrive at the nozzle, the cells become encapsulated within the drop in a controlled manner. This technique has been utilized to encapsulate single cells with throughputs on the order of 15 kHz,12 a significant improvement over previous studies reporting encapsulation rates on the order of 60-160 Hz.4,15 In the controlled encapsulation work, over 80% of drops contained one and only one cell, a significant efficiency improvement over Poisson (random) statistics, which predicts less than 40% efficiency on average.12
In previous controlled encapsulation work,12 the average number of particles per drop &lambda; was tuned to provide single-cell encapsulation. We hypothesize that through tuning of flow rates, we can efficiently encapsulate any number of cells per drop when &lambda; is equal or close to the number of desired cells per drop. While single-cell encapsulation is valuable in determining individual cell responses from stimuli, multiple-cell encapsulation provides information relating to the interaction of controlled numbers and types of cells. Here we present a protocol, representative results using polystyrene microspheres, and discussion for controlled encapsulation of multiple cells using a passive inertial ordering channel and drop generation nozzle.

Watch this Scientific Journal Video about High Throughput Single-cell and Multiple-cell Micro-encapsulation at JoVE.com

High Throughput Single-cell and Multiple-cell Micro-encapsulation

Das Kombinieren der monodispersen Tropfenerzeugung mit Beschleunigungssensoren Anordnung von Zellen und Partikeln, beschreiben wir ein Verfahren, um eine gewünschte Anzahl von Zellen oder Teilchen in einem einzelnen Tropfen mit kHz Preise zu kapseln. Wir demonstrieren die Effizienz zweimal höher sind als die von ungeordneten Kapselung für Single-und Double-Teilchen-Tropfen.

High-Throughput-Einzel-Zell-und Multiple-Zelle Mikroverkapselung

Microfluidic encapsulation methods have been previously utilized to capture cells in picoliter-scale aqueous, monodisperse drops, providing confinement ...

Research

JoVE Journal

Bioengineering

Polymer Microarrays for High Throughput Discovery of Biomaterials

Polymer Microarrays für High Throughput Discovery of Biomaterials

The discovery of novel biomaterials that are optimized for a specific biological application is readily achieved using polymer microarrays, which allows a ...

Forschung

Biotechnik

High-throughput Protein Expression Generator Using a Microfluidic Platform

High-throughput Protein Expression Generator mit einem mikrofluidischen Plattform

Rapidly increasing fields, such as systems biology, require the development and implementation of new technologies, enabling high-throughput and ...

Combinatorial Synthesis of and High-throughput Protein Release from Polymer Film and Nanoparticle Libraries

Kombinatorische Synthese von und High-Throughput-Protein Release von Polymer Film-und Nanopartikel-Bibliotheken

Polyanhydrides are a class of biomaterials with excellent biocompatibility and drug delivery capabilities. While they have been studied extensively with ...

High-throughput Synthesis of Carbohydrates and Functionalization of Polyanhydride Nanoparticles

Hochdurchsatz-Synthese von Kohlenhydraten und Funktionalisierung von Nanopartikeln Polyanhydrid

Transdisciplinary approaches involving areas such as material design, nanotechnology, chemistry, and immunology have to be utilized to rationally design ...

High Throughput Microfluidic Rapid and Low Cost Prototyping Packaging Methods

In this work, 3 different packaging and assembly techniques are presented. They can be classified into two categories: one-time use and reusable packaging ...

Using Tomoauto: A Protocol for High-throughput Automated Cryo-electron Tomography

Verwendung Tomoauto: Ein Protokoll für die Hochdurchsatz-Automated Kryo-Elektronentomographie

Cryo-electron tomography (Cryo-ET) is a powerful three-dimensional (3-D) imaging technique for visualizing macromolecular complexes in their native ...

A Microfluidic Platform for High-throughput Single-cell Isolation and Culture

Ein Mikrofluidik-Plattform für Hochdurchsatz-Einzelzell-Isolierung und Kultur

Studying the heterogeneity of single cells is crucial for many biological questions, but is technically difficult. Thus, there is a need for a simple, yet ...

High-throughput Identification of Bacteria Repellent Polymers for Medical Devices

Hochdurchsatz-Identifizierung von Bakterien abstoßenden Polymere für medizinische Geräte

Medical devices are often associated with hospital-acquired infections, which place enormous strain on patients and the healthcare system as well as ...

3D Microtissues for Injectable Regenerative Therapy and High-throughput Drug Screening

3D Microtissues für injizierbare Regenerative Therapie und Hochdurchsatz-Drogen-Screening

To upgrade traditional 2D cell culture to 3D cell culture, we have integrated microfabrication with cryogelation technology to produce macroporous ...

An Ultrahigh-throughput Microfluidic Platform for Single-cell Genome Sequencing

Eine höchste Durchsatz mikrofluidischen Plattform für einzellige Genom-Sequenzierung

Sequencing technologies have undergone a paradigm shift from bulk to single-cell resolution in response to an evolving understanding of the role of ...