This material is based on work supported by the Office of Naval Research award number N00014-13-1-0074 (to V.N.), the Human Frontier Science Program grant number RGP0037/2015 (to V.N.), and the Binational Science Foundation grant 2014400 (to V.N.).

<ol>
	<li>Carlson, E. D., Gan, R., Hodgman, C. E., Jewett, M. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell-free+protein+synthesis:+Applications+come+of+age.">Cell-free protein synthesis: Applications come of age.</a> Biotechnol Adv. , (2011).</li><li>Hodgman, C. E., Jewett, M. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell-free+synthetic+biology:+Thinking+outside+the+cell.">Cell-free synthetic biology: Thinking outside the cell.</a> Metab Eng. , (2011).</li><li>Caschera, F., Noireaux, V. <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+2.3+mg/mL+of+protein+with+an+all+Escherichia+coli+cell-free+transcription-translation+system.">Synthesis of 2.3 mg/mL of protein with an all Escherichia coli cell-free transcription-translation system.</a> Biochimie. 99, 162-168 (2014).</li><li>Shin, J., Noireaux, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+E.+coli+cell-free+expression+toolbox:+application+to+synthetic+gene+circuits+and+artificial+cells.">An E. coli cell-free expression toolbox: application to synthetic gene circuits and artificial cells.</a> ACS Synth Biol. 1 (1), 29-41 (2012).</li><li>Chemla, Y., Ozer, E., Schlesinger, O., Noireaux, V., Alfonta, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetically+expanded+cell-free+protein+synthesis+using+endogenous+pyrrolysyl+orthogonal+translation+system.">Genetically expanded cell-free protein synthesis using endogenous pyrrolysyl orthogonal translation system.</a> Biotechnol Bioeng. , (2015).</li><li>Hong, S. 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M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Linear+DNA+for+Rapid+Prototyping+of+Synthetic+Biological+Circuits+in+an+Escherichia+coli+Based+TX-TL+Cell-Free+System.">Linear DNA for Rapid Prototyping of Synthetic Biological Circuits in an Escherichia coli Based TX-TL Cell-Free System.</a> Acs Synthetic Biology. 3 (6), 387-397 (2014).</li><li>Takahashi, M. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterizing+and+prototyping+genetic+networks+with+cell-free+transcription-translation+reactions.">Characterizing and prototyping genetic networks with cell-free transcription-translation reactions.</a> Methods. , (2015).</li><li>Shin, J., Jardine, P., Noireaux, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genome+Replication,+Synthesis,+and+Assembly+of+the+Bacteriophage+T7+in+a+Single+Cell-Free+Reaction.">Genome Replication, Synthesis, and Assembly of the Bacteriophage T7 in a Single Cell-Free Reaction.</a> ACS Synthetic Biology. 1 (9), 408-413 (2012).</li><li>Garamella, J., Marshall, R., Rustad, M., Noireaux, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+All+E.+coli+TX-TL+Toolbox+2.0:+A+Platform+for+Cell-Free+Synthetic+Biology.">The All E. coli TX-TL Toolbox 2.0: A Platform for Cell-Free Synthetic Biology.</a> ACS Synth Biol. , (2016).</li><li>Karzbrun, E., Shin, J., Bar-Ziv, R. H., Noireaux, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coarse-grained+dynamics+of+protein+synthesis+in+a+cell-free+system.">Coarse-grained dynamics of protein synthesis in a cell-free system.</a> Phys Rev Lett. 106 (4), 048104 (2011).</li><li>Daube, S. S., Arad, T., Bar-Ziv, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell-free+co-synthesis+of+protein+nanoassemblies:+tubes,+rings,+and+doughnuts.">Cell-free co-synthesis of protein nanoassemblies: tubes, rings, and doughnuts.</a> Nano Lett. 7 (3), 638-641 (2007).</li><li>Chen, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+immunoblot+assay+reveals+that+bacteriophage+T4+thymidylate+synthase+and+dihydrofolate+reductase+are+not+virion+proteins.">An immunoblot assay reveals that bacteriophage T4 thymidylate synthase and dihydrofolate reductase are not virion proteins.</a> J Virol. 69 (4), 2119-2125 (1995).</li><li>Sun, Z. Z., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Protocols+for+implementing+an+Escherichia+coli+based+TX-TL+cell-free+expression+system+for+synthetic+biology.">Protocols for implementing an Escherichia coli based TX-TL cell-free expression system for synthetic biology.</a> J Vis Exp. (79), e50762 (2013).</li><li>Shin, J. N. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+cell-free+expression+with+the+endogenous+E.+coli+RNA+polymerase+and+sigma+factor+70.">Efficient cell-free expression with the endogenous E. coli RNA polymerase and sigma factor 70.</a> J Biol Eng. , (2010).</li><li>Caschera, F., Noireaux, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+of+amino+acid+mixtures+for+cell-free+expression+systems.">Preparation of amino acid mixtures for cell-free expression systems.</a> Biotechniques. 58 (1), 40-43 (2015).</li><li>Minton, 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=How+can+biochemical+reactions+within+cells+differ+from+those+in+test+tubes.">How can biochemical reactions within cells differ from those in test tubes.</a> J Cell Sci. 119, 2863-2869 (2006).</li><li>Minton, 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=Implications+of+macromolecular+crowding+for+protein+assembly.">Implications of macromolecular crowding for protein assembly.</a> Curr Opin Struct Biol. 10 (1), 34-39 (2000).</li><li>Zimmerman, S. B., Minton, 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=Macromolecular+crowding:+biochemical,+biophysical,+and+physiological+consequences.">Macromolecular crowding: biochemical, biophysical, and physiological consequences.</a> Annu Rev Biophys Biomol Struct. 22, 27-65 (1993).</li></ol>

The authors declare the following competing financial interest(s): Noireaux laboratory receives research funds from MYcroarray, a distributor of the MYtxtl cell-free protein expression kit.

Following the technique in Chen, et al.14 for SPMC, a critical step is reached when determining the proper conditions for superinfection. The parameter that most closely controls a host strain&#39;s ability to withstand superinfection is frequently the initial concentration of the infecting phage. The host cells must be in logarithmic growth phase before initial infection with a very small amount of phage. Eventually, the phage will also reach logarithmic growth and the goal is to allow t...

Over the past decade, the cell-free expression technology has been engineered to address novel applications in emergent multidisciplinary research areas related to synthetic and quantitative biology. Originally used to express proteins independent of a living organism, new cell-free TXTL systems have been developed for both basic and applied sciences1,2, broadening considerably the scope of this technology. The new generation of TXTL platforms has been designed to be user friendly, more efficient (reaching 2 mg/mL of protein synthesis in batch mode3), more versatile at the level of transcription4, and modular so as to easily integrate novel natural or synthetic functions that expand the capabilities of existing biological systems5,6. In particular, cell-free TXTL systems have become handy for the rapid prototyping of genetic programs, such as regulatory elements or small genetic circuits7,8,9, by reducing the design-build-test cycle to a few days. Remarkably, the new TXTL systems are also capable of processing large DNA programs such as the complete synthesis of coliphages10,11, demonstrating strong enough performances to support the reconstitution of active genomic DNA encoded living entities.
TXTL systems present many technical advantages compared to traditional in vitro constructive biochemical assays. Cell-free TXTL links the process of gene expression to the final product in a reduced and open environment, as opposed to the complex cytoplasm of a living cell. TXTL uses DNA to reconstruct biochemical systems in vitro, which, with modern DNA assembly techniques, is affordable and fast in addition to not requiring fastidious protein purification steps. Cell-free expression provides direct access to most of the components in the biochemical reactions, thus allowing a deeper dissection of the molecular interactions12. In a TXTL reaction, one can change the biochemical and biophysical settings at will, which is almost impossible in a living cell. Given these advantages and recent improvements, the TXTL technology is becoming more and more popular as an alternative platform for synthetic and quantitative biology. While the research community using TXTL is rapidly growing and TXTL is becoming a standard technology in bioengineering, it is essential to understand how to use such platforms so as to develop adequate practices related to the execution of TXTL reactions and to the interpretation of the results.
In this article, we describe how to use an all E. coli TXTL system to synthesize, in one-pot reactions, bacteriophages from their genome11, such as MS2 (RNA, 3.4 kb), &#934;&#935;174 (ssDNA, 5.4 kb), and T7 (dsDNA, 40 kb). We show how the amount of phages synthesized changes with respect to some of the biochemical settings of the reactions (magnesium and potassium concentrations). Molecular crowding, emulated through a range of PEG 8000 concentrations, has a dramatic effect on phage synthesis over several orders of magnitude. The realization of such large biochemical systems in single test tube reactions that recapitulate concurrently the processes of transcription, translation, and self-assembly, is interesting for addressing basic questions related to biology and biophysics10 (gene regulation, self-assembly), as well as for developing applications, such as repurposing phage functions to build new nanostructures13. In addition to a practical on TXTL, we provide methods for phage amplification, genome extraction and purification, and phage quantification by the plaque assay. The methods presented in this manuscript are appropriate for researchers who use E. coli extract based cell-free systems and are interested in bacteriophages.
The protocols presented in this work can be summarized as follow: 1) Phage amplification (Day 1: prepare inoculation cells, day 2: single plaque, multiple phage growth, and concentration, and day 3: purification of phage), 2) Double-stranded genome DNA extraction (phenol/chloroform extraction), and 3) Cell-free phage reaction and titer experiment (Day 1: plate host cells and make agar plates, day 2: cell-free reaction and host cell pre-culture, and day 3: host cell culture and phage titer).

<table><tbody><tr><td>Ultracentrifugation tubes</td><td>Beckman Coulter</td><td>344057</td><td></td></tr><tr><td>Conical tubes</td><td>Falcon</td><td>352070</td><td></td></tr><tr><td>Gradient maker</td><td>BioComp Gradient Master</td><td>see Anal Biochem. 1985 Jul;148(1):254-9.</td><td></td></tr><tr><td>Syringe and Blunt Cannula</td><td>Monoject</td><td>8881513918 and 888202017</td><td></td></tr><tr><td>Wide-bore pipette tips</td><td>Fischerbrand</td><td>02-707-134</td><td></td></tr><tr><td>Plaque counter</td><td>New Brunswik Scientific</td><td>Colony Counter Model C-110</td><td></td></tr><tr><td>Culture tubes</td><td>Fischerbrand</td><td>14-961-33</td><td></td></tr><tr><td>Cell-free system</td><td>Mycroarray Inc</td><td>Mytxtl</td><td></td></tr><tr><td>BioComp Gradient Master</td><td>BioComp Instruments</td><td>Model 105ME</td><td></td></tr><tr><td>LB agar plate recipe</td><td></td><td></td><td>25 g/L Luria-Bertani medium (LB Broth, Miller - Fisher BioReagents product number BP1426) and 15 g/L Bacto-Agar solid (Brenton, Dickenson and Company - product number 214010).</td></tr></tbody></table>

synthesis of infectious bacteriophages in an e. coli-based cell-free expression system

A new generation of cell-free transcription-translation (TXTL) systems, engineered to have a greater versatility and modularity, provide novel capabilities to perform basic and applied sciences in test tube reactions. Over the past decade, cell-free TXTL has become a powerful technique for a broad range of novel multidisciplinary research areas related to quantitative and synthetic biology. The new TXTL platforms are particularly useful to construct and interrogate biochemical systems through the execution of synthetic or natural gene circuits. In vitro TXTL has proven convenient to rapidly prototype regulatory elements and biological networks as well as to recapitulate molecular self-assembly mechanisms found in living systems. In this article, we describe how infectious bacteriophages, such as MS2 (RNA), &#934;&#935;174 (ssDNA), and T7 (dsDNA), are entirely synthesized from their genome in one-pot reactions using an all Escherichia coli, cell-free TXTL system. Synthesis of the three coliphages is quantified using the plaque assay. We show how the yield of synthesized phage depends on the biochemical settings of the reactions. Molecular crowding, emulated through a controlled concentration of PEG 8000, affects the amount of synthesized phages by orders of magnitudes. We also describe how to amplify the phages and how to purify their genomes. The set of protocols and results presented in this work should be of interest to multidisciplinary researchers involved in cell-free synthetic biology and bioengineering.

We show four representative results. In Figure 1, we present a set of negative controls to ensure that the cell-free TXTL system and the phage DNA stocks are not contaminated with living E. coli cells. We verify that the cell-free TXTL system is free of intact E. coli cell contamination by plating both a non-incubated and incubated reaction solution void of genomic DNA (Figure 1A and <strong cla...

Watch this Scientific Journal Video about Synthesis of Infectious Bacteriophages in an E. coli-based Cell-free Expression System at JoVE.com

Synthesis of Infectious Bacteriophages in an E. coli-based Cell-free Expression System

A new generation of cell-free transcription-translation platforms has been engineered to construct biochemical systems in vitro through the execution of gene circuits. In this article, we describe how bacteriophages, such as MS2, &#934;&#935;174, and T7, are synthesized from their genome using an all E. coli cell-free TXTL system.

Synthesis of Infectious Bacteriophages in an E. coli-based Cell-free Expression System

A new generation of cell-free transcription-translation (TXTL) systems, engineered to have a greater versatility and modularity, provide novel ...

synthesis-infectious-bacteriophages-an-e-coli-based-cell-free

Research

JoVE Journal

Bioengineering

14.5K Views.  University of Minnesota. A new generation of cell-free transcription-translation platforms has been engineered to construct biochemical systems in vitro through the execution of gene circuits. In this article, we describe how bacteriophages, such as MS2, ΦΧ174, and T7, are synthesized from their genome using an all E. coli cell-free TXTL system.

Video: Synthesis of Infectious Bacteriophages in an E. coli-based Cell-free Expression System

Following Cell-fate in E. coli After Infection by Phage Lambda

The system comprising bacteriophage (phage) lambda and the bacterium E. coli has long served as a paradigm for cell-fate determination1,2. Following the simultaneous infection of the cell by a number of phages, one of two pathways is chosen: lytic (virulent) or lysogenic (dormant)3,4. We recently developed a method for fluorescently labeling individual phages, and were able to examine the post-infection decision in real-time under the microscope, at the level of individual phages and cells5. Here, we describe the full procedure for performing the infection experiments described in our earlier work5. This includes the creation of fluorescent phages, infection of the cells, imaging under the microscope and data analysis. The fluorescent phage is a "hybrid", co-expressing wild- type and YFP-fusion versions of the capsid gpD protein. A crude phage lysate is first obtained by inducing a lysogen of the gpD-EYFP (Enhanced Yellow Fluorescent Protein) phage, harboring a plasmid expressing wild type gpD. A series of purification steps are then performed, followed by DAPI-labeling and imaging under the microscope. This is done in order to verify the uniformity, DNA packaging efficiency, fluorescence signal and structural stability of the phage stock. The initial adsorption of phages to bacteria is performed on ice, then followed by a short incubation at 35&deg;C to trigger viral DNA injection6. The phage/bacteria mixture is then moved to the surface of a thin nutrient agar slab, covered with a coverslip and imaged under an epifluorescence microscope. The post-infection process is followed for 4 hr, at 10 min interval. Multiple stage positions are tracked such that ~100 cell infections can be traced in a single experiment. At each position and time point, images are acquired in the phase-contrast and red and green fluorescent channels. The phase-contrast image is used later for automated cell recognition while the fluorescent channels are used to characterize the infection outcome: production of new fluorescent phages (green) followed by cell lysis, or expression of lysogeny factors (red) followed by resumed cell growth and division. The acquired time-lapse movies are processed using a combination of manual and automated methods. Data analysis results in the identification of infection parameters for each infection event (e.g. number and positions of infecting phages) as well as infection outcome (lysis/lysogeny). Additional parameters can be extracted if desired.

Following Cell-fate in E. coli After Infection by Phage Lambda

This article describes the procedure for preparing a fluorescently-labeled version of bacteriophage lambda, infection of E. coli bacteria, following the infection outcome under the microscope, and analysis of infection results.

The system comprising bacteriophage (phage) lambda and the bacterium E. coli has long served as a paradigm for cell-fate determination1,2. Following the ...

Immunology and Infection

Large Insert Environmental Genomic Library Production

The vast majority of microbes in nature currently remain inaccessible to traditional cultivation methods. Over the past decade, culture-independent environmental genomic (i.e. metagenomic) approaches have emerged, enabling researchers to bridge this cultivation gap by capturing the genetic content of indigenous microbial communities directly from the environment. To this end, genomic DNA libraries are constructed using standard albeit artful laboratory cloning techniques. Here we describe the construction of a large insert environmental genomic fosmid library with DNA derived from the vertical depth continuum of a seasonally hypoxic fjord. This protocol is directly linked to a series of connected protocols including coastal marine water sampling [1], large volume filtration of microbial biomass [2] and a DNA extraction and purification protocol [3]. At the outset, high quality genomic DNA is end-repaired with the creation of 5 -phosphorylated blunt ends. End-repaired DNA is subjected to pulsed-field gel electrophoresis (PFGE) for size selection and gel extraction is performed to recover DNA fragments between 30 and 60 thousand base pairs (Kb) in length. Size selected DNA is purified away from the PFGE gel matrix and ligated to the phosphatase-treated blunt-end fosmid CopyControl vector pCC1 (EPICENTRE <a href="http://www.epibio.com/item.asp?ID=385">http://www.epibio.com/item.asp?ID=385</a>). Linear concatemers of pCC1 and insert DNA are subsequently headfull packaged into phage particles by lambda terminase, with subsequent infection of phage-resistant E. coli cells. Successfully transduced clones are recovered on LB agar plates under antibiotic selection and archived in 384-well plate format using an automated colony picking robot (Qpix2, GENETIX). The current protocol draws from various sources including the CopyControl Fosmid Library Production Kit from EPICENTRE and the published works of multiple research groups [4-7]. Each step is presented with best practice in mind. Whenever possible we highlight subtleties in execution to improve overall quality and efficiency of library production. The whole process of fosmid library production and automated colony picking takes at least 7-10 days as there are many incubation steps included. However, there are several stopping points possible which are mentioned within the protocol.

Construction of a fosmid library with environmental genomic DNA isolated from the vertical depth continuum of a seasonally hypoxic fjord is described. The resulting clone library is picked into 384-well plates and archived for downstream sequencing and functional screening by the application of an automated colony picking system.

The vast majority of microbes in nature currently remain inaccessible to traditional cultivation methods. Over the past decade, culture-independent ...

Biology

Escherichia coli-Based Cell-Free Protein Synthesis: Protocols for a robust, flexible, and accessible platform technology

Over the last 50 years, Cell-Free Protein Synthesis (CFPS) has emerged as a powerful technology to harness the transcriptional and translational capacity of cells within a test tube. By obviating the need to maintain the viability of the cell, and by eliminating the cellular barrier, CFPS has been foundational to emerging applications in biomanufacturing of traditionally challenging proteins, as well as applications in rapid prototyping for metabolic engineering, and functional genomics. Our methods for implementing an E. coli-based CFPS platform allow new users to access many of these applications. Here, we describe methods to prepare extract through the use of enriched media, baffled flasks, and a reproducible method of tunable sonication-based cell lysis. This extract can then be used for protein expression capable of producing 900 &#181;g/mL or more of super folder green fluorescent protein (sfGFP) in just 5 h from experimental setup to data analysis, given that appropriate reagent stocks have been prepared beforehand. The estimated startup cost of obtaining reagents is $4,500 which will sustain thousands of reactions at an estimated cost of $0.021 per &#181;g of protein produced or $0.019 per &#181;L of reaction. Additionally, the protein expression methods mirror the ease of the reaction setup seen in commercially available systems due to optimization of reagent pre-mixes, at a fraction of the cost. In order to enable the user to leverage the flexible nature of the CFPS platform for broad applications, we have identified a variety of aspects of the platform that can be tuned and optimized depending on the resources available and the protein expression outcomes desired.

Escherichia coli-Based Cell-Free Protein Synthesis: Protocols for a robust, flexible, and accessible platform technology

This protocol details the steps, costs, and equipment necessary to generate E. coli-based cell extracts and implement in vitro protein synthesis reactions within 4 days or less. To leverage the flexible nature of this platform for broad applications, we discuss reaction conditions that can be adapted and optimized.

Over the last 50 years, Cell-Free Protein Synthesis (CFPS) has emerged as a powerful technology to harness the transcriptional and translational capacity ...

Chemistry

CFPS Protocols for Micro-Compartmentalized Synthetic Cells

Cell-Free Protein Synthesis System for Building Synthetic Cells

The Cell-Free Protein Synthesis (CFPS) system has been widely employed to facilitate the bottom-up assembly of synthetic cells. It serves as the host for the core machinery of the Central Dogma, standing as an optimal chassis for the integration and assembly of diverse artificial cellular mimicry systems. Despite its frequent use in the fabrication of synthetic cells, establishing a tailored and robust CFPS system for a specific application remains a nontrivial challenge. In this methods paper, we present a comprehensive protocol for the CFPS system, routinely employed in constructing synthetic cells. This protocol encompasses key stages in the preparation of the CFPS system, including the cell extract, template preparation, and routine expression optimization utilizing a fluorescent reporter protein. Additionally, we show representative results by encapsulating the CFPS system within various micro-compartments, such as monolayer droplets, double-emulsion vesicles, and chambers situated atop supported lipid bilayers. Finally, we elucidate the critical steps and conditions necessary for the successful assembly of these CFPS systems in distinct environments. We expect that our approach will facilitate the establishment of good working practices among various laboratories within the continuously expanding synthetic cell community, thereby accelerating progress in the field of synthetic cell development.

Author Spotlight: Optimizing CFPS Systems for Synthetic Cell Construction

This protocol describes the Cell-Free Protein Synthesis (CFPS) system used in constructing synthetic cells. It outlines key stages with representative results in different micro-compartments. The protocol aims to establish best practices for diverse laboratories in the synthetic cell community, advancing progress in synthetic cell development.

The Cell-Free Protein Synthesis (CFPS) system has been widely employed to facilitate the bottom-up assembly of synthetic cells. It serves as the host for ...

Biochemistry

Functional Surface-immobilization of Genes Using Multistep Strand Displacement Lithography

Immobilization of genes on lithographically structured surfaces allows the study of compartmentalized gene expression processes in an open microfluidic bioreactor system. In contrast to other approaches towards artificial cellular systems, such a setup allows for a continuous supply with gene expression reagents and simultaneous draining of waste products. This facilitates the implementation of cell-free gene expression processes over extended periods of time, which is important for the realization of dynamic gene regulatory feedback systems. Here we provide a detailed protocol for the fabrication of genetic biochips using a simple-to-use lithographic technique based on DNA strand displacement reactions, which exclusively uses commercially available components. We also provide a protocol on the integration of compartmentalized genes with a polydimethylsiloxane (PDMS)-based microfluidic system. Furthermore, we show that the system is compatible with total internal reflection fluorescence (TIRF) microscopy, which can be used for the direct observation of molecular interactions between DNA and molecules contained in the expression mix.

We describe a simple lithographic procedure for the immobilization of gene-length DNA molecules on a surface, which can be used to perform cell-free gene expression experiments on biochips.

Immobilization of genes on lithographically structured surfaces allows the study of compartmentalized gene expression processes in an open microfluidic ...

Preparing Protein Producing Synthetic Cells using Cell Free Bacterial Extracts, Liposomes and Emulsion Transfer

The bottom-up assembly approach for construction of synthetic cells is an effective tool for isolating and investigating cellular processes in a cell mimicking environment. Furthermore, the development of cell-free expression systems has demonstrated the ability to reconstitute the protein production, transcription and translation processes (DNA&#8594;RNA&#8594;protein) in a controlled manner, harnessing synthetic biology. Here we describe a protocol for preparing a cell-free expression system, including the production of a potent bacterial lysate and encapsulating this lysate inside cholesterol-rich lipid-based giant unilamellar vesicles (GUVs) (i.e., stable liposomes), to form synthetic cells. The protocol describes the methods for preparing the components of the synthetic cells including the production of active bacterial lysates, followed by a detailed step-by-step preparation of the synthetic cells based on a water-in-oil emulsion transfer method. These facilitate the production of millions of synthetic cells in a simple and affordable manner with a high versatility for producing different types of proteins. The obtained synthetic cells can be used to investigate protein/RNA production and activity in an isolated environment, in directed evolution, and also as a controlled drug delivery platform for on-demand production of therapeutic proteins inside the body.

This protocol describes the method, materials, equipment and steps for bottom-up preparation of RNA and protein producing synthetic cells. The inner aqueous compartment of the synthetic cells contained the S30 bacterial lysate encapsulated within a lipid bilayer (i.e., stable liposomes), using a water-in-oil emulsion transfer method.

The bottom-up assembly approach for construction of synthetic cells is an effective tool for isolating and investigating cellular processes in a cell ...

From Cells to Cell-Free Protein Synthesis within 24 Hours Using Cell-Free Autoinduction Workflow

Cell-free protein synthesis (CFPS) has grown as a biotechnology platform that captures transcription and translation machinery in vitro. Numerous developments have made the CFPS platform more accessible to new users and have expanded the range of applications. For lysate based CFPS systems, cell extracts can be generated from a variety of organisms, harnessing the unique biochemistry of that host to augment protein synthesis. Within the last 20 years, Escherichia coli (E. coli) has become one of the most widely used organisms for supporting CFPS due to its affordability and versatility. Despite numerous key advances, the workflow for E. coli cell extract preparation has remained a key bottleneck for new users to implement CFPS for their applications. The extract preparation workflow is time-intensive and requires technical expertise to achieve reproducible results. To overcome these barriers, we previously reported the development of a 24 hour cell-free autoinduction (CFAI) workflow that reduces user input and technical expertise required. The CFAI workflow minimizes the labor and technical skill required to generate cell extracts while also increasing the total quantities of cell extracts obtained. Here we describe that workflow in a step-by-step manner to improve access and support the broad implementation of E. coli based CFPS.

This work describes the preparation of cell extract from Escherichia coli (E. coli) followed by cell-free protein synthesis (CFPS) reactions in under 24 hours. Explanation of the cell-free autoinduction (CFAI) protocol details improvements made to reduce researcher oversight and increase quantities of cell extract obtained.

Cell-free protein synthesis (CFPS) has grown as a biotechnology platform that captures transcription and translation machinery in vitro. Numerous ...

Protocols for Implementing an Escherichia coli Based TX-TL Cell-Free Expression System for Synthetic Biology

Ideal cell-free expression systems can theoretically emulate an in vivo cellular environment in a controlled in vitro platform.1 This is useful for expressing proteins and genetic circuits in a controlled manner as well as for providing a prototyping environment for synthetic biology.2,3 To achieve the latter goal, cell-free expression systems that preserve endogenous Escherichia coli transcription-translation mechanisms are able to more accurately reflect in vivo cellular dynamics than those based on T7 RNA polymerase transcription. We describe the preparation and execution of an efficient endogenous E. coli based transcription-translation (TX-TL) cell-free expression system that can produce equivalent amounts of protein as T7-based systems at a 98% cost reduction to similar commercial systems.4,5 The preparation of buffers and crude cell extract are described, as well as the execution of a three tube TX-TL reaction. The entire protocol takes five days to prepare and yields enough material for up to 3000 single reactions in one preparation. Once prepared, each reaction takes under 8 hr from setup to data collection and analysis. Mechanisms of regulation and transcription exogenous to E. coli, such as lac/tet repressors and T7 RNA polymerase, can be supplemented.6 Endogenous properties, such as mRNA and DNA degradation rates, can also be adjusted.7 The TX-TL cell-free expression system has been demonstrated for large-scale circuit assembly, exploring biological phenomena, and expression of proteins under both T7- and endogenous promoters.6,8 Accompanying mathematical models are available.9,10 The resulting system has unique applications in synthetic biology as a prototyping environment, or "TX-TL biomolecular breadboard."

Protocols for Implementing an Escherichia coli Based TX-TL Cell-Free Expression System for Synthetic Biology

This five-day protocol outlines all steps, equipment, and supplemental software necessary for creating and running an efficient endogenous Escherichia coli based TX-TL cell-free expression system from scratch. With reagents, the protocol takes 8 hours or less to setup a reaction, collect, and process data.

Ideal cell-free expression systems can theoretically emulate an in vivo cellular environment in a controlled in vitro platform.1 This is useful for ...

Exploring Gut Phage-Bacteria Dynamics in Murine Models Using T4 Phage

T4 Bacteriophage and E. coli Interaction in the Murine Intestine: A Prototypical Model for Studying Host-Bacteriophage Dynamics In Vivo

Bacteriophages (phages) are viruses that infect bacteria with species- and strain-level specificity and are the most abundant biological entities across all known ecosystems. Within bacterial communities, such as those found in the gut microbiota, phages are implicated in regulating microbiota population dynamics and driving bacterial evolution. There has been renewed interest in phage research in the last decade, in part due to the host-specific killing capabilities of lytic phages, which offer a promising tool to counter the increasing threat of antimicrobial resistant bacteria. Furthermore, recent studies demonstrating that phages adhere to intestinal mucus suggest they may have a protective role in preventing bacterial invasion into the underlying epithelium. Importantly, like bacterial microbiomes, disrupted phageomes have been associated with worsened outcomes in diseases such as inflammatory bowel disease. Previous studies have demonstrated that phages can modulate the microbiome of animals and humans through fecal filtrate transplants, benefiting the host&#39;s health. With this recent wave of research comes the necessity to establish and standardize protocols for studying phages in the context of the gut microbiome. This protocol provides a set of procedures to study isolated T4 phages and their bacterial host, Escherichia coli,&#160;in the context of the murine gastrointestinal tract. The methods described here outline&#160;how to start from a phage lysate, administer it to mice and assess effects on bacterial host and phage levels.&#160;This protocol can be modified and applied to other phage-bacterial pairs and provides a starting point for studying host-phage dynamics in vivo.

Author Spotlight: Investigating Bacteriophage-Induced Immune Responses in Gnotobiotic Mice

Bacteriophages (phages), viruses that infect bacteria, are an integral component of the gut microbiome. Though these symbiotic inhabitants drive bacterial fitness and population dynamics, little is understood about how they impact gut homeostasis and disease. This protocol studies isolated T4 phages within a mouse model, adaptable to other phage-bacterial pairs.

Bacteriophages (phages) are viruses that infect bacteria with species- and strain-level specificity and are the most abundant biological entities across ...

HeLa Based Cell Free Expression Systems for Expression of Plasmodium Rhoptry Proteins

Malaria causes significant global morbidity and mortality. No routine vaccine is currently available. One of the major reasons for lack of a vaccine is the challenge of identifying suitable vaccine candidates. Malarial proteins expressed using prokaryotic and eukaryotic cell based expression systems are poorly glycosylated, generally insoluble and undergo improper folding leading to reduced immunogenicity. The wheat germ, rabbit reticulocyte lysate and Escherichia coli lysate cell free expression systems are currently used for expression of malarial proteins. However, the length of expression time and improper glycosylation of proteins still remains a challenge. We demonstrate expression of Plasmodium proteins in vitro using HeLa based cell free expression systems, termed &#8220;in vitro human cell free expression systems&#8221;. The 2 HeLa based cell free expression systems transcribe mRNA in 75 min and 3 &#181;l of transcribed mRNA is sufficient to translate proteins in 90 min. The 1-step expression system is a transcription and translation coupled expression system; the transcription and co-translation occurs in 3 hr. The process can also be extended for 6 hr by providing additional energy. In the 2-step expression system, mRNA is first transcribed and then added to the translation mix for protein expression. We describe how to express malaria proteins; a hydrophobic PF3D7_0114100 Maurer&#8217;s Cleft &#8211; 2 transmembrane (PfMC-2TM) protein, a hydrophilic PF3D7_0925900 protein and an armadillo repeats containing protein PF3D7_1361800, using the HeLa based cell free expression system. The proteins are expressed in micro volumes employing 2-step and 1-step expression strategies. An affinity purification method to purify 25 &#181;l of proteins expressed using the in vitro human cell free expression system is also described. Protein yield is determined by Bradford&#8217;s assay and the expressed and purified proteins can be confirmed by western blotting analysis. Expressed recombinant proteins can be used for immunizations, immunoassays and protein sequencing.

HeLa Based Cell Free Expression Systems for Expression of Plasmodium Rhoptry Proteins

Expression of malarial proteins in cell based systems remains challenging. We demonstrate two step and one step IVT (in vitro translation) cell free expression systems for expressing malarial recombinant rhoptry proteins from HeLa cells. We use a Ni-resin affinity based purification system to purify the rhoptry proteins.

Malaria causes significant global morbidity and mortality. No routine vaccine is currently available. One of the major reasons for lack of a vaccine is ...

Synthesis of Infectious Bacteriophages in an E. coli-based Cell-free Expression System

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Chapters in this video

Following Cell-fate in E. coli After Infection by Phage Lambda

Large Insert Environmental Genomic Library Production

Escherichia coli-Based Cell-Free Protein Synthesis: Protocols for a robust, flexible, and accessible platform technology

Cell-Free Protein Synthesis System for Building Synthetic Cells

Functional Surface-immobilization of Genes Using Multistep Strand Displacement Lithography

Preparing Protein Producing Synthetic Cells using Cell Free Bacterial Extracts, Liposomes and Emulsion Transfer

From Cells to Cell-Free Protein Synthesis within 24 Hours Using Cell-Free Autoinduction Workflow

Protocols for Implementing an Escherichia coli Based TX-TL Cell-Free Expression System for Synthetic Biology

T4 Bacteriophage and E. coli Interaction in the Murine Intestine: A Prototypical Model for Studying Host-Bacteriophage Dynamics In Vivo

HeLa Based Cell Free Expression Systems for Expression of Plasmodium Rhoptry Proteins