Name: a robust method for the large-scale production of spheroids for high-content screening and analysis applications
Uploaded: 2021-12-28T14:00:00
Description: Watch this Scientific Journal Video about A Robust Method for the Large-Scale Production of Spheroids for High-Content Screening and Analysis Applications at JoVE.com

The authors acknowledge the support of an infrastructure research grant from Science Foundation Ireland (SFI) (16/RI/3745) to JCS. Work in the UCD Cell Screening Laboratory is supported by the UCD College of Science. ASC is funded by an Irish Research Council (IRC) Government of Ireland Postgraduate Scholarship (GOIPG/2019/68). The authors also thank all members of the lab for their input and helpful discussions. The artwork in Figure 1 was generated in BioRender.

1. Cell culture
<ol>
	<li>Prepare media
	<ol>
		<li>Prepare specific cell culture media depending on the type of cell line. Ensure that all media for cell maintenance contains 10% Foetal Bovine Serum (FBS). 
		NOTE: Different cell lines use different media. HT-29 colon carcinoma cells (ATCC HTB-38) are grown in McCoys 5A + 10% FBS. HepG2 hepatocellular carcinoma cells (ATCC HB-8065) are grown in Minimum Essential Medium + 1% L-glutamine + 10% FBS. H358 bronchoalveolar carcinoma cells (ATCC CRL-580...

<ol>
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F., Yang, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three-dimensional+cell+culture+systems+and+their+applications+in+drug+discovery+and+cell-based+biosensors.">Three-dimensional cell culture systems and their applications in drug discovery and cell-based biosensors.</a> Assay and Drug Development Technologies. 12 (4), 207-218 (2014).</li><li>Lv, D., Hu, Z., Lu, L., Lu, H., Xu, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three-dimensional+cell+culture:+A+powerful+tool+in+tumor+research+and+drug+discovery.">Three-dimensional cell culture: A powerful tool in tumor research and drug discovery.</a> Oncology Letters. 14 (6), 6999-7010 (2017).</li><li>Zhang, X., Jiang, T., Chen, D., Wang, Q., Zhang, L. 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C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+High-throughput+automated+confocal+microscopy+platform+for+quantitative+phenotyping+of+nanoparticle+uptake+and+transport+in+spheroids.">A High-throughput automated confocal microscopy platform for quantitative phenotyping of nanoparticle uptake and transport in spheroids.</a> Small. 15 (37), 1902033 (2019).</li><li>Kelly, S., Byrne, M. H., Quinn, S. J., Simpson, 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=Multiparametric+nanoparticle-induced+toxicity+readouts+with+single+cell+resolution+in+HepG2+multicellular+tumour+spheroids.">Multiparametric nanoparticle-induced toxicity readouts with single cell resolution in HepG2 multicellular tumour spheroids.</a> Nanoscale. 13 (41), 17615-17628 (2021).</li><li>Sirenko, O., Mitlo, T., Hesley, J., Luke, S., Owens, W., Cromwell, E. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-content+assays+for+characterizing+the+viability+and+morphology+of+3D+cancer+spheroid+cultures.">High-content assays for characterizing the viability and morphology of 3D cancer spheroid cultures.</a> Assay and Drug Development Technologies. 13 (7), 402-414 (2015).</li><li>Redondo-Castro, E., Cunningham, C. J., Miller, J., Cain, S. A., Allan, S. M., Pinteaux, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Generation+of+human+mesenchymal+stem+cell+3D+spheroids+using+low-binding+plates.">Generation of human mesenchymal stem cell 3D spheroids using low-binding plates.</a> Bio-protocol. 8 (16), (2018).</li><li>Lee, G. Y., Kenny, P. A., Lee, E. H., Bissell, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three-dimensional+culture+models+of+normal+and+malignant+breast+epithelial+cells.">Three-dimensional culture models of normal and malignant breast epithelial cells.</a> Nature Methods. 4 (4), 359-365 (2007).</li><li>Eismann, B., 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=Automated+3D+light-sheet+screening+with+high+spatiotemporal+resolution+reveals+mitotic+phenotypes.">Automated 3D light-sheet screening with high spatiotemporal resolution reveals mitotic phenotypes.</a> Journal of Cell Science. 133 (11), 245043 (2020).</li><li>Alsehli, H., 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+integrated+pipeline+for+high-throughput+screening+and+profiling+of+spheroids+using+simple+live+image+analysis+of+frame+to+frame+variations.">An integrated pipeline for high-throughput screening and profiling of spheroids using simple live image analysis of frame to frame variations.</a> Methods. 190, 33-43 (2021).</li><li>Stirling, D. 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The approach described here details a platform for generating several hundred spheroids per well in a manner that is suitable for HCS and HCA. In comparison to other popular methods, such as the use of flat-bottomed and round-bottomed ULA plates, which allow the formation of only one spheroid per well18,19, this method provides the opportunity for high-resolution information to be extracted from large numbers of spheroids in a screening format. Notably, this meth...

Traditionally, cell-based assays have been performed in monolayers growing on a solid substrate, which effectively can be considered as a two-dimensional (2D) environment. However, it is becoming increasingly recognized that 2D cell culture models lack physiological relevance in some contexts and cannot replicate many of the complex interactions that occur between cells1. Three-dimensional (3D) cell culture methods are rapidly becoming popular among researchers, and 3D cell models show high potential to better mimic the physiological conditions encountered by cells in the tissue environment2. There are several different types of 3D cell assemblies that have been employed, but the two most common types are spheroids and organoids. Spheroids can be grown from many different cell lines, and they can adopt various shapes and sizes depending on the cell type used and their method of assembly3. Moreover, spheroids can also be referred to as multicellular tumor spheroids (MCTS) when they are grown from cancer cell lines, and these models have found particular use for preclinical in vitro drug delivery and toxicity studies4,5. Organoids, on the other hand, aim to better mimic the tissues and organs in our body and can adopt more complex morphological arrangements. The production of organoids involves the use of adult stem cells or pluripotent stem cells, which can be reprogrammed into the appropriate cells to resemble the tissue or organ of interest. They are primarily used to investigate the development of organs and to model diseases and host-pathogen interactions6.
There is a range of different methods used to generate 3D cell assemblies. Scaffold-based methods provide a substrate or support to which cells can either attach or grow within. These scaffolds can have various shapes and can be made from a variety of different materials. The most common are extracellular matrix (ECM) components and hydrogels, and they are designed to resemble the natural extracellular environment of cells and thereby facilitate physiological interactions4,7. ECM basement material has been extracted from Engelbreth-Holm-Swarm mouse sarcoma tumor and shown to contain a rich mixture of ECM components, including laminin, type IV collagen, and perlecan8. However, despite its advantageous composition, there are two main challenges with its use, namely its batch-to-batch variability and that it has two different aggregate states below and above 10 &#176;C8,9. In contrast, hydrogels have the advantage of being flexible with respect to their components and rigidity, and they can be customized to suit the specific 3D cell assembly desired7,10. Scaffold-based methods are essential for organoid growth but are also widely used for spheroids. Scaffold-free methods, which work by preventing cells from attaching to the surface they are growing on, are usually only compatible with spheroid assembly. Examples include ultra-low attachment (ULA) plates, with either a flat bottom or U-bottom, which allow aggregation of the cells into spheroids, or the use of continuous agitation of the cells in spinner/rotation flasks10.
The use of 3D cell assemblies to study a wide variety of biological events is rapidly gaining popularity; however, it is essential that the method chosen for their culture is appropriate and compatible with the plans for their downstream analysis. For example, the use of ULA plates generates spheroids of high consistency; however, this method is restricted to the production of a single spheroid per well, thereby limiting throughput. Particular consideration is needed when fluorescence imaging of the 3D structure is planned. The substrate or plate on which the assembly is grown needs to be optically compatible, and care must be taken to minimize the effects of light scattering caused by any scaffolds that may have been used11. This particular problem becomes more acute as the numerical aperture of the microscope objective lenses increases.
Arguably one of the major reasons for selecting to work with a 3D cell model is to extract volumetric imaging data about not only the entire assembly but also the individual cells within it. MCTS models, in particular, are beginning to prove very powerful for deepening our understanding of how therapeutics transit from the outside to central cells (as they would need to in a tumor)12, and so gaining knowledge from individual cells at different layers is essential. The imaging technology that extracts quantitative information from individual cells is termed high-content analysis (HCA) and is a powerful approach in the context of screening13. To date, HCA has almost exclusively been applied to monolayer cultures, but there is an increasing realization that this approach has the power to be applied to 3D cultures enabling a wide range of cellular functions and processes to be studied14. It would have the clear advantage that large numbers of 3D assemblies could be analyzed, potentially providing cell-level data from across each structure. However, challenges associated with imaging of potentially thick cell assemblies, as well as the large data sets generated, need to be overcome.
In this article, a robust scaffold-based method for the large-scale production of MCTS in a 96-well format is presented. The method facilitates the production of several hundred 3D cell assemblies in each well. Examples are shown for three different cell types, representing solid tumor models of the liver, lung, and colon. The spheroids that form can be of a variety of sizes, and so HCA is used to select structures of a particular size and/or morphology. This feature provides the additional advantage that any phenotypes observed can be compared across spheroids of different sizes, but all treated in the same way in the same well. This approach is compatible with high-resolution imaging, importantly providing both cell-level and subcellular level quantitative data from the same cellular assemblies. This method of spheroid production has the additional advantage over methods that generate a single spheroid per well, that the large numbers of spheroids produced in each well potentially provide sufficient biomass for other downstream analyses, such as transcriptome and proteome profiling.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>0.05% Trypsin-EDTA (1x), phenol red</td>
			<td>Gibco</td>
			<td>25300054</td>
			<td></td>
		</tr>
		<tr>
			<td>Bovine Serum Albumin (BSA)</td>
			<td>Sigma Aldrich</td>
			<td>A6003</td>
			<td></td>
		</tr>
		<tr>
			<td>Calcium chloride</td>
			<td>Fisher Scientific</td>
			<td>10050070</td>
			<td></td>
		</tr>
		<tr>
			<td>CellCarrier-96 Ultra Microplates, tissue culture treated, black, 96-well with lid</td>
			<td>Perkin Elmer</td>
			<td>6055302</td>
			<td>These plates have been renamed as Phenoplates</td>
		</tr>
		<tr>
			<td>Dimethyl sulfoxide (DMSO)</td>
			<td>Sigma Aldrich</td>
			<td>D2650</td>
			<td></td>
		</tr>
		<tr>
			<td>Foetal Bovine Serum (FBS), qualified, EU approved, South America origin, heat inactivated</td>
			<td>Gibco</td>
			<td>10500064</td>
			<td></td>
		</tr>
		<tr>
			<td>Glycine</td>
			<td>Fisher Scientific</td>
			<td>BP381-1</td>
			<td></td>
		</tr>
		<tr>
			<td>Goat anti-Mouse IgG (H+L) Highly Cross-Adsorbed Secondary Antibody, Alexa Fluor 488</td>
			<td>Invitrogen</td>
			<td>A-11029</td>
			<td></td>
		</tr>
		<tr>
			<td>L-Glutamine solution, 200 mM</td>
			<td>Gibco</td>
			<td>25030024</td>
			<td></td>
		</tr>
		<tr>
			<td>Hoechst 33342</td>
			<td>Sigma Aldrich</td>
			<td>14533</td>
			<td></td>
		</tr>
		<tr>
			<td>Magnesium chloride</td>
			<td>Fisher Scientific</td>
			<td>10647032</td>
			<td></td>
		</tr>
		<tr>
			<td>Matrigel Basement Membrane Matrix, Phenol Red-free, LDEV-free, 10 mL</td>
			<td>Corning</td>
			<td>356237</td>
			<td>This Matrigel formulation can be also found with the same catalogue number at BD Biosciences</td>
		</tr>
		<tr>
			<td>Matrigel Growth Factor Reduced Matrigel</td>
			<td>BD Biosciences</td>
			<td>356231</td>
			<td>This Matrigel formulation can be also found with the same catalogue number at Corning</td>
		</tr>
		<tr>
			<td>McCoy&#39;s 5A medium</td>
			<td>Gibco</td>
			<td>26600023</td>
			<td></td>
		</tr>
		<tr>
			<td>McCoy&#39;s 5A medium with L glutamine and sodium bicarbonate, without phenol red</td>
			<td>Hyclone</td>
			<td>10358633</td>
			<td></td>
		</tr>
		<tr>
			<td>Minimum Essential Medium (MEM)</td>
			<td>Gibco</td>
			<td>21090022</td>
			<td></td>
		</tr>
		<tr>
			<td>Minimum Essential Medium (MEM), without glutamine, without phenol red</td>
			<td>Gibco</td>
			<td>51200046</td>
			<td></td>
		</tr>
		<tr>
			<td>Mouse monoclonal anti-LAMP1 antibody (concentrate)</td>
			<td>Developmental Studies Hybridoma Bank</td>
			<td>H4A3-a</td>
			<td></td>
		</tr>
		<tr>
			<td>Neubauer counting chamber</td>
			<td>Hirschmann</td>
			<td>8100203</td>
			<td></td>
		</tr>
		<tr>
			<td>Nunclon tissue culture dish with lid, polystyrene, 92 mm x 17 mm</td>
			<td>ThermoFisher Scientific</td>
			<td>150350</td>
			<td></td>
		</tr>
		<tr>
			<td>Opera Phenix HCS System and Harmony HCA software</td>
			<td>Perkin Elmer</td>
			<td>HCSHH14000000</td>
			<td></td>
		</tr>
		<tr>
			<td>Paraformaldehyde (PFA)</td>
			<td>Sigma Aldrich</td>
			<td>P6148</td>
			<td></td>
		</tr>
		<tr>
			<td>Phalloidin Alexa Fluor 568</td>
			<td>Invitrogen</td>
			<td>A12380</td>
			<td></td>
		</tr>
		<tr>
			<td>Phosphate Buffered Saline (PBS) tablets</td>
			<td>Sigma Aldrich</td>
			<td>P4417</td>
			<td></td>
		</tr>
		<tr>
			<td>Polysorbate 20</td>
			<td>Sigma Aldrich</td>
			<td>P5927</td>
			<td></td>
		</tr>
		<tr>
			<td>RPMI 1640 Medium, GlutaMAX Supplement</td>
			<td>Gibco</td>
			<td>61870010</td>
			<td></td>
		</tr>
		<tr>
			<td>RPMI 1640 Medium, without glutamine, without phenol red</td>
			<td>Gibco</td>
			<td>11835063</td>
			<td></td>
		</tr>
		<tr>
			<td>Triton X-100</td>
			<td>Sigma Aldrich</td>
			<td>T9284</td>
			<td></td>
		</tr>
		<tr>
			<td>Stericup sterile vacuum filter units</td>
			<td>Millipore</td>
			<td>SCGVU05RE</td>
			<td></td>
		</tr>
	</tbody>
</table>

a robust method for the large-scale production of spheroids for high-content screening and analysis applications

High-content screening (HCS) and high-content analysis (HCA) are technologies that provide researchers with the ability to extract large-scale quantitative phenotypic measurements from cells. This approach has proved powerful for deepening our understanding of a wide range of both fundamental and applied events in cell biology. To date, the majority of applications for this technology have relied on the use of cells grown in monolayers, although it is increasingly realized that such models do not recapitulate many of the interactions and processes that occur in tissues. As such, there has been an emergence in the development and use of 3-dimensional (3D) cell assemblies, such as spheroids and organoids. Although these 3D models are particularly powerful in the context of cancer biology and drug delivery studies, their production and analysis in a reproducible manner suitable for HCS and HCA present a number of challenges. The protocol detailed here describes a method for the generation of multicellular tumor spheroids (MCTS), and demonstrates that it can be applied to three different cell lines in a manner that is compatible with HCS and HCA. The method facilitates the production of several hundred spheroids per well, providing the specific advantage that when used in a screening regime, data can be obtained from several hundred structures per well, all treated in an identical manner. Examples are also provided, which detail how to process the spheroids for high-resolution fluorescence imaging and how HCA can extract quantitative features at both the spheroid level as well as from individual cells within each spheroid. This protocol could easily be applied to answer a wide range of important questions in cell biology.

In this protocol, a robust method to produce 3D cell culture assemblies in the form of spheroids, using different cell types to represent various tumor tissues, is detailed. This method allows for the generation of hundreds of spheroids per well, which enables cell-based assays to be performed in a high-content manner (Figure 1). This approach has previously been used to study nanoparticle uptake in HT-29 spheroids16 and nanoparticle-induced toxicity in HepG2 spheroid...

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A Robust Method for the Large-Scale Production of Spheroids for High-Content Screening and Analysis Applications

This protocol details a method for the production of three different types of spheroids in a manner that makes them suitable for large-scale high-content screening and analysis. In addition, examples are presented showing how they can be analyzed at spheroid and individual cell levels.

High-content screening (HCS) and high-content analysis (HCA) are technologies that provide researchers with the ability to extract large-scale ...

This protocol provides a method to produce several hundred multicellular tumorous spheroids in each well of a multi well plate suitable for automated microscopy. Spheroid produced can be categorized into different size classes, and subcellular information can be extracted from every cell. The technique produces sufficient serums that can be used in direct screening and RNA interference studies.Dilute ECM basement material in cold phenol red serum free medium using pre chilled tips kept at minus 20 degrees Celsius. I bet 15 microliters of the ECM basement material and medium solution into a 96 well imaging plate. Centrifuge the plate for 20 minutes at 91 times G at four degrees Celsius.Incubate the plate for no longer than 30 minutes at 37 degrees Celsius. Add trips and EDTA to the cells. Incubate the cells at 37 degrees Celsius at the end of incubation, we suspend the cells in a complete medium containing 10%FBS.Pipette 10 microliters of the cell suspension, into a hemocytometer counting chamber. Count the number of cells in four quadrants of the chamber. Centra views the cells at 135 times G for four minutes at room temperature.One this cells are pelleted, aspirate the supernatant and resuspend the cells in a phenol red free complete medium to obtain a concentration of 10 to the six cells per milliliter. Dilute the cells in a phenol red free complete medium. See the cells dropwise in a circular motion in a total volume of 35 microliters per well.Incubate the cells for one hour at 37 degrees Celsius in a humidified incubator with 5%carbon dioxide. At 1.2 microliters of ECM basement material to 23.8 microliters of phenol red free complete medium per well, resulting in a final volume of 60 microliters per well. Incubate the cells at 37 degrees Celsius in a humidified incubator with 5%carbon dioxide.The following day, replace the medium with 100 microliters of fresh phenol red free complete medium. Insert the 96 well plate containing spheroids, into a confocal high content screening microscope. Select the appropriate lasers to excite the floors used.Acquire the channels sequentially to avoid crosstalk, image the spheroids using appropriate objectives. To analyze the morphology of spheroids, segment the spheroids based on the fluorescently conjugated FLoid and staining. Segment the nuclei based on the hex three, three, three, four, two staining.Segment the cytoplasm of each cell by the residual hex three, three, four, two, stain that is present in the cell cytoplasm. Calculate different morphological properties of the spheroids including volume, surface area, sphericity and the number of nuclei per his spheroids. Ross has images further to remove spheroids smaller than 75 cubic micrometers and a larger than 900, 000 cubic micrometers.To analyze a single cell within spheroids, segment the spheroids based on the fluorescently conjugated spheroid staining. Segment the nuclei based on the hex three, three, three, four, two staining. Segment the cytoplasm of each cell by the residual hex three, three, three, four, two stain that is present in the cell cytoplasm.Segment the lysosomes based on the secondary antibody staining. Calculate different morphological properties of the cells within each spheroid, including the number of lysosomes per cell, cell volume and cell surface area. The figure shows well overviews of three different types of spheroids, including images at different confocal planes.A volumetric view of the entire spheroids is also shown. The figure shows the pH segmentation process, panel A shows the entire spheroids in a volumetric view. Panel B displays the set segmentation of the cytoplasm, the nuclei and the lysosomes within all cells of a single spheroids.The cytoplasm and nuclei are segmented based on the hex three, three, three, four, two staining. And lysosomes are segmented based on the anti lab one antibody staining. Panels C shows the same segmented as panel B, but in a three plain view.Various morphological measurements at the spheroids level can be made. These measurements include calculation of the number of nuclei per spheroids, as well as these Felicity, volume, and surface area of the pH. The typical volume of each cell in the three spheroid types.As well as the number of lysosomes per cell are shown in this figure. Optimizing the initial cell seating density at the start of SP generation is a critical step. The figure shows that adding too many cells still allows spheroids formation.However, this can result in the fusion if spheroids. Spheroids produce in this manner can be subjected to transcriptomic and proteomic analysis. This technique is used to quantitatively analyze the uptake of drug delivery such nano particles and assess their toxicity to individual cells in the spheroids.

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A Neuronal and Astrocyte Co-Culture Assay for High Content Analysis of Neurotoxicity

High Content Analysis (HCA) assays combine cells and detection reagents with automated imaging and powerful image analysis algorithms, allowing measurement of multiple cellular phenotypes within a single assay. In this study, we utilized HCA to develop a novel assay for neurotoxicity. Neurotoxicity assessment represents an important part of drug safety evaluation, as well as being a significant focus of environmental protection efforts. Additionally, neurotoxicity is also a well-accepted in vitro marker of the development of neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. Recently, the application of HCA to neuronal screening has been reported. By labeling neuronal cells with &beta;III-tubulin, HCA assays can provide high-throughput, non-subjective, quantitative measurements of parameters such as neuronal number, neurite count and neurite length, all of which can indicate neurotoxic effects. However, the role of astrocytes remains unexplored in these models. Astrocytes have an integral role in the maintenance of central nervous system (CNS) homeostasis, and are associated with both neuroprotection and neurodegradation when they are activated in response to toxic substances or disease states. GFAP is an intermediate filament protein expressed predominantly in the astrocytes of the CNS. Astrocytic activation (gliosis) leads to the upregulation of GFAP, commonly accompanied by astrocyte proliferation and hypertrophy. This process of reactive gliosis has been proposed as an early marker of damage to the nervous system. The traditional method for GFAP quantitation is by immunoassay. This approach is limited by an inability to provide information on cellular localization, morphology and cell number. We determined that HCA could be used to overcome these limitations and to simultaneously measure multiple features associated with gliosis - changes in GFAP expression, astrocyte hypertrophy, and astrocyte proliferation - within a single assay. In co-culture studies, astrocytes have been shown to protect neurons against several types of toxic insult and to critically influence neuronal survival. Recent studies have suggested that the use of astrocytes in an in vitro neurotoxicity test system may prove more relevant to human CNS structure and function than neuronal cells alone. Accordingly, we have developed an HCA assay for co-culture of neurons and astrocytes, comprised of protocols and validated, target-specific detection reagents for profiling &beta;III-tubulin and glial fibrillary acidic protein (GFAP). This assay enables simultaneous analysis of neurotoxicity, neurite outgrowth, gliosis, neuronal and astrocytic morphology and neuronal and astrocytic development in a wide variety of cellular models, representing a novel, non-subjective, high-throughput assay for neurotoxicity assessment. The assay holds great potential for enhanced detection of neurotoxicity and improved productivity in neuroscience research and drug discovery.

This article describes a novel protocol and reagent set designed for sensitive measurement of neurotoxic effects of compounds and treatments on co-cultures of neurons and astrocytes using high content analysis. Results demonstrate that high content analysis represents an exciting novel technology for neurotoxicity assessment.

High Content Analysis (HCA) assays combine cells and detection reagents with automated imaging and powerful image analysis algorithms, allowing ...

Batch Immunostaining for Large-Scale Protein Detection in the Whole Monkey Brain

Immunohistochemistry (IHC) is one of the most widely used laboratory techniques for the detection of target proteins in situ. Questions concerning the expression pattern of a target protein across the entire brain are relatively easy to answer when using IHC in small brains, such as those of rodents. However, answering the same questions in large and convoluted brains, such as those of primates presents a number of challenges. Here we present a systematic approach for immunodetection of target proteins in an adult monkey brain. This approach relies on the tissue embedding and sectioning methodology of NeuroScience Associates (NSA) as well as tools developed specifically for batch-staining of free-floating sections. It results in uniform staining of a set of sections which, at a particular interval, represents the entire brain. The resulting stained sections can be subjected to a wide variety of analytical procedures in order to measure protein levels, the population of neurons expressing a certain protein.

Large-scale immunodetection of target proteins across the entire primate brain is possible by employing novel tissue embedding and sectioning methods combined with the use of creative apparatus for batch staining of multiple free-floating sections at a given time.

Immunohistochemistry (IHC) is one of the most widely used laboratory techniques for the detection of target proteins in situ. Questions concerning the ...

Infinium Assay for Large-scale SNP Genotyping Applications

Genotyping variants in the human genome has proven to be an efficient method to identify genetic associations with phenotypes. The distribution of variants within families or populations can facilitate identification of the genetic factors of disease. Illumina&#39;s panel of genotyping BeadChips allows investigators to genotype thousands or millions of single nucleotide polymorphisms (SNPs) or to analyze other genomic variants, such as copy number, across a large number of DNA samples. These SNPs can be spread throughout the genome or targeted in specific regions in order to maximize potential discovery. The Infinium assay has been optimized to yield high-quality, accurate results quickly. With proper setup, a single technician can process from a few hundred to over a thousand DNA samples per week, depending on the type of array. This assay guides users through every step, starting with genomic DNA and ending with the scanning of the array. Using propriety reagents, samples are amplified, fragmented, precipitated, resuspended, hybridized to the chip, extended by a single base, stained, and scanned on either an iScan or Hi Scan high-resolution optical imaging system. One overnight step is required to amplify the DNA. The DNA is denatured and isothermally amplified by whole-genome amplification; therefore, no PCR is required. Samples are hybridized to the arrays during a second overnight step. By the third day, the samples are ready to be scanned and analyzed. Amplified DNA may be stockpiled in large quantities, allowing bead arrays to be processed every day of the week, thereby maximizing throughput.

A protocol is described that uses Illumina&#39;s Infinium assays to perform large-scale genotyping. These assays can reliably genotype millions of SNPs across hundreds of individual DNA samples in three days. Once generated, these genotypes can be used to check for associations with a variety of different diseases or phenotypes.

Genotyping variants in the human genome has proven to be an efficient method to identify genetic associations with phenotypes. The distribution of ...

Large-scale Gene Knockdown in C. elegans Using dsRNA Feeding Libraries to Generate Robust Loss-of-function Phenotypes

RNA interference by feeding worms bacteria expressing dsRNAs has been a useful tool to assess gene function in C. elegans. While this strategy works well when a small number of genes are targeted for knockdown, large scale feeding screens show variable knockdown efficiencies, which limits their utility. We have deconstructed previously published RNAi knockdown protocols and found that the primary source of the reduced knockdown can be attributed to the loss of dsRNA-encoding plasmids from the bacteria fed to the animals. Based on these observations, we have developed a dsRNA feeding protocol that greatly reduces or eliminates plasmid loss to achieve efficient, high throughput knockdown. We demonstrate that this protocol will produce robust, reproducible knock down of C. elegans genes in multiple tissue types, including neurons, and will permit efficient knockdown in large scale screens. This protocol uses a commercially available dsRNA feeding library and describes all steps needed to duplicate the library and perform dsRNA screens. The protocol does not require the use of any sophisticated equipment, and can therefore be performed by any C. elegans lab.

Large-scale Gene Knockdown in C. elegans Using dsRNA Feeding Libraries to Generate Robust Loss-of-function Phenotypes

While dsRNA feeding in C. elegans is a powerful tool to assess gene function, current protocols for large scale feeding screens result in variable knockdown efficiencies. We describe an improved protocol for performing large scale RNAi feeding screens that results in highly efficacious and reproducible knockdown of gene expression.

RNA interference by feeding worms bacteria expressing dsRNAs has been a useful tool to assess gene function in C. elegans. While this strategy works well ...

A Strategy for Sensitive, Large Scale Quantitative Metabolomics

Metabolite profiling has been a valuable asset in the study of metabolism in health and disease. However, current platforms have different limiting factors, such as labor intensive sample preparations, low detection limits, slow scan speeds, intensive method optimization for each metabolite, and the inability to measure both positively and negatively charged ions in single experiments. Therefore, a novel metabolomics protocol could advance metabolomics studies. Amide-based hydrophilic chromatography enables polar metabolite analysis without any chemical derivatization. High resolution MS using the Q-Exactive (QE-MS) has improved ion optics, increased scan speeds (256 msec at resolution 70,000), and has the capability of carrying out positive/negative switching. Using a cold methanol extraction strategy, and coupling an amide column with QE-MS enables robust detection of 168 targeted polar metabolites and thousands of additional features simultaneously.&#160; Data processing is carried out with commercially available software in a highly efficient way, and unknown features extracted from the mass spectra can be queried in databases.

Metabolite profiling has been a valuable asset in the study of metabolism in health and disease. Utilizing normal-phased liquid chromatography coupled to high-resolution mass spectrometry with polarity switching and a rapid duty cycle, we describe a protocol to analyze the polar metabolic composition of biological material with high sensitivity, accuracy, and resolution.

Metabolite profiling has been a valuable asset in the study of metabolism in health and disease. However, current platforms have different limiting ...

High Content Screening Analysis to Evaluate the Toxicological Effects of Harmful and Potentially Harmful Constituents (HPHC)

Cigarette smoke (CS) is a major risk factor for cardiovascular and lung diseases. Because CS is a complex aerosol containing more than 7,000 chemicals1 it is challenging to assess the contributions of individual constituents to its overall toxicity. Toxicological profiles of individual constituents as well as mixtures can be however established in vitro, by applying high through-put screening tools, which enable the profiling of Harmful and Potentially Harmful Constituents (HPHCs) of tobacco smoke, as defined by the U.S. Food and Drug Administration (FDA).2
For an initial assessment, an impedance-based instrument was used for a real-time, label-free assessment of the compound&#39;s toxicity. The instrument readout relies on cell adhesion, viability and morphology that all together provide an overview of the cell status. A dimensionless parameter, named cell index, is used for quantification. A set of different staining protocols was developed for a fluorescence imaging-based investigation and a HCS platform was used to gain more in-depth information on the kind of cytotoxicity elicited by each HPHC.
Of the 15 constituents tested, only five were selected for HCS-based analysis as they registered a computable LD50 (&#60; 20 mM). These included 1-aminonaphtalene, Arsenic (V), Chromium (VI), Crotonaldehyde and Phenol. Based on their effect in the HCS, 1-aminonaphtalene and Phenol could be identified to induce mitochondrial dysfunction, and, together with Chromium (VI) as genotoxic based on the increased histone H2AX phosphorylation. Crotonaldehyde was identified as an oxidative stress inducer and Arsenic as a stress kinase pathway activator.
This study demonstrates that a combination of impedance-based and HCS technologies provides a robust tool for in vitro assessment of CS constituents.

High Content Screening Analysis to Evaluate the Toxicological Effects of Harmful and Potentially Harmful Constituents HPHC

The objective of the study was to assess the biological impact of 15 cigarette smoke constituents using a combination of an impedance-based real time cell analyzer and a high-content screening (HCS)-based platform for toxicological assessment in vitro. This study provides information on effective doses, toxicity and modes of action of the tested compounds.

Cigarette smoke (CS) is a major risk factor for cardiovascular and lung diseases. Because CS is a complex aerosol containing more than 7,000 chemicals1 it ...

Open Source High Content Analysis Utilizing Automated Fluorescence Lifetime Imaging Microscopy

We present an open source high content analysis instrument utilizing automated fluorescence lifetime imaging (FLIM) for assaying protein interactions using F&#246;rster resonance energy transfer (FRET) based readouts of fixed or live cells in multiwell plates. This provides a means to screen for cell signaling processes read out using intramolecular FRET biosensors or intermolecular FRET of protein interactions such as oligomerization or heterodimerization, which can be used to identify binding partners. We describe here the functionality of this automated multiwell plate FLIM instrumentation and present exemplar data from our studies of HIV Gag protein oligomerization and a time course of a FRET biosensor in live cells. A detailed description of the practical implementation is then provided with reference to a list of hardware components and a description of the open source data acquisition software written in &#181;Manager. The application of FLIMfit, an open source MATLAB-based client for the OMERO platform, to analyze arrays of multiwell plate FLIM data is also presented. The protocols for imaging fixed and live cells are outlined and a demonstration of an automated multiwell plate FLIM experiment using cells expressing fluorescent protein-based FRET constructs is presented. This is complemented by a walk-through of the data analysis for this specific FLIM FRET data set.

We present an open source high content analysis (HCA) instrument utilizing automated fluorescence lifetime imaging (FLIM) for assaying protein interactions using F&#246;rster resonance energy transfer (FRET) based readouts. Data acquisition for this openFLIM-HCA instrument is controlled by software written in &#181;Manager and data analysis is undertaken in FLIMfit.

We present an open source high content analysis instrument utilizing automated fluorescence lifetime imaging (FLIM) for assaying protein interactions ...

ODELAY: A Large-scale Method for Multi-parameter Quantification of Yeast Growth

Growth phenotypes of microorganisms are a strong indicator of their underlying genetic fitness and can be segregated into 3 growth regimes: lag-phase, log-phase, and stationary-phase. Each growth phase can reveal different aspects of fitness that are related to various environmental and genetic conditions. High-resolution and quantitative measurements of all 3 phases of growth are generally difficult to obtain. Here we present a detailed method to characterize all 3 growth phases on solid media using an assay called One-cell Doubling Evaluation of Living Arrays of Yeast (ODELAY). ODELAY quantifies growth phenotypes of individual cells growing into colonies on solid media using time-lapse microscopy. This method can directly observe population heterogeneity with each growth parameter in genetically identical cells growing into colonies. This population heterogeneity offers a unique perspective for understanding genetic and epigenetic regulation, and responses to genetic and environmental perturbations. While the ODELAY method is demonstrated using yeast, it can be utilized on any colony forming microorganism that is visible by bright field microscopy.

We present a method for quantifying growth phenotypes of individual yeast cells as they grow into colonies on solid media using time-lapse microscopy termed, One-cell Doubling Evaluation of Living Arrays of Yeast (ODELAY). Population heterogeneity of genetically identical cells growing into colonies can be directly observed and quantified.

Growth phenotypes of microorganisms are a strong indicator of their underlying genetic fitness and can be segregated into 3 growth regimes: lag-phase, ...

A Semiautomated ChIP-Seq Procedure for Large-scale Epigenetic Studies

Chromatin immunoprecipitation followed by sequencing (ChIP-Seq) is a powerful and widely used approach to profile chromatin DNA associated with specific histone modifications, such as H3K27ac, to help identify cis-regulatory DNA elements. The manual process to complete a ChIP-Seq is labor intensive, technically challenging, and often requires large-cell numbers (&#62;100,000 cells). The method described here helps to overcome those challenges. A complete semiautomated, microscaled H3K27ac ChIP-Seq procedure including cell fixation, chromatin shearing, immunoprecipitation, and sequencing library preparation, for batch of 48 samples for cell number inputs less than 100,000 cells is described in detail. The semiautonomous platform reduces technical variability, improves signal-to-noise ratios, and drastically reduces labor. The system can thereby reduce costs by allowing for reduced reaction volumes, limiting the number of expensive reagents such as enzymes, magnetic beads, antibodies, and hands-on time required. These improvements to the ChIP-Seq method suit perfectly for large-scale epigenetic studies of clinical samples with limited cell numbers in a highly reproducible manner.

This paper describes a semiautomated, microscaled ChIP-Seq protocol of DNA regions associated with a specific histone modification (H3K27ac) using a ChIP liquid-handler platform, followed by library preparation using tagmentation. The procedure includes control assessment for quality and quantity purposes and can be adopted to other histone modifications or transcription factors.

Chromatin immunoprecipitation followed by sequencing (ChIP-Seq) is a powerful and widely used approach to profile chromatin DNA associated with specific ...

A Simple Dry Sectioning Method for Obtaining Whole-Seed-Sized Resin Section and Its Applications

The morphology, size and quantity of cells, starch granules&#160;and protein bodies in seed determine the weight and quality of seed. They are significantly different among different regions of seed. In order to view the morphologies of cells, starch granules and protein bodies clearly, and quantitatively analyze their morphology parameters accurately, the whole-seed-sized section is needed. Though the whole-seed-sized paraffin section can investigate the accumulation of storage materials in seeds, it is very difficult to quantitatively analyze the morphology parameters of cells and storage materials due to the low resolution of the thick section. The thin resin section has high resolution, but the routine resin sectioning method is not suitable to prepare the whole-seed-sized section of mature seeds with a large volume and high starch content. In this study, we present a simple dry sectioning method for preparing the whole-seed-sized resin section. The technique can prepare the cross and longitudinal whole-seed-sized sections of developing, mature, germinated, and cooked seeds embedded in LR White resin, even for large seeds with high starch content. The whole-seed-sized section can be stained with fluorescent brightener 28, iodine, and Coomassie brilliant blue R250 to specifically exhibit the morphology of cells, starch granules, and protein bodies clearly, respectively. The image obtained can also be analyzed quantitatively to show the morphology parameters of cells, starch granules, and protein bodies in different regions of seed.

This technique allows for the fast and simple preparation of whole-seed-sized resin section for the observation and analysis of cells, starch granules, and protein bodies in different regions of the seed.