Name: plate-based large-scale cultivation of caenorhabditis elegans: sample preparation for the study of metabolic alterations in diabetes
Uploaded: 2018-08-24T14:00:00
Description: Watch this Scientific Journal Video about Plate-based Large-scale Cultivation of Caenorhabditis elegans: Sample Preparation for the Study of Metabolic Alterations in Diabetes at JoVE.com

This study was supported by the Deutsche Forschungsgemeinschaft (DFG) within the IRTG 1874 &#34;Diabetic microvascular complications&#34; and CRC 1118 &#34;Reactive metabolites as a cause for diabetic late complications&#34;. C. elegans strains N2 and CL2166 were provided by the CGC, which is funded by the NIH Office of Research Infrastructure Programs (P40 OD010440).

NOTE: This protocol is divided into five sections. In sections 1&#8211;3, the main protocol to culture C. elegans at a large-scale is presented. Sections 4 and 5 provide additional protocols for the assessment of exemplified metabolites occurring in diabetic metabolites. In detail, section 1 describes a general large-scale culture on plates. Section 2 focuses on the transfer of large amounts of C. elegans, whereas section 3 explains the harvesting of a large-scale sample. Section 4 explains the protein ...

<ol>
	<li>Fronius, M., Clauss, W. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechano-sensitivity+of+ENaC:+may+the+(shear)+force+be+with+you.">Mechano-sensitivity of ENaC: may the (shear) force be with you.</a> Pfl&#252;gers Archiv. 455 (5), 775-785 (2008).</li><li>Stiernagle, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Maintenance+of+C.+elegans.">Maintenance of C. elegans.</a> WormBook. , (2006).</li><li>Sohn, E. 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=Retinal+neurodegeneration+may+precede+microvascular+changes+characteristic+of+diabetic+retinopathy+in+diabetes+mellitus.">Retinal neurodegeneration may precede microvascular changes characteristic of diabetic retinopathy in diabetes mellitus.</a> Proceedings of the National Academy of Sciences. 113 (19), E2655-E2664 (2016).</li><li>Chilelli, N. C., Burlina, S., Lapolla, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=AGEs,+rather+than+hyperglycemia,+are+responsible+for+microvascular+complications+in+diabetes:+a+&amp;#34;glycoxidation-centric&amp;#34;+point+of+view.">AGEs, rather than hyperglycemia, are responsible for microvascular complications in diabetes: a &amp;#34;glycoxidation-centric&amp;#34; point of view.</a> Nutrition, Metabolism &amp; Cardiovascular Diseases. 23 (10), 913-919 (2013).</li><li> Schlotterer, A., 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=C.+elegans+as+model+for+the+study+of+high+glucose-+mediated+life+span+reduction.">C. elegans as model for the study of high glucose- mediated life span reduction.</a> Diabetes. 58 (11), 2450-2456 (2009).</li><li>Sutphin, G. L., Kaeberlein, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measuring+Caenorhabditis+elegans+life+span+on+solid+media.">Measuring Caenorhabditis elegans life span on solid media.</a> Journal of Visualized Experiments. (27), e1152 (2009).</li><li>Leiers, 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=A+stress-responsive+glutathione+S-transferase+confers+resistance+to+oxidative+stress+in+Caenorhabditis+elegans.">A stress-responsive glutathione S-transferase confers resistance to oxidative stress in Caenorhabditis elegans.</a> Free Radical Biology and Medicine. 34 (11), 1405-1415 (2003).</li><li>Rabbani, N., Thornalley, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurement+of+methylglyoxal+by+stable+isotopic+dilution+analysis+LC-MS/MS+with+corroborative+prediction+in+physiological+samples.">Measurement of methylglyoxal by stable isotopic dilution analysis LC-MS/MS with corroborative prediction in physiological samples.</a> Nature Protocols. 9 (8), 1969-1979 (2014).</li><li>Bradford, M. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+rapid+and+sensitive+method+for+the+quantitation+of+microgram+quantities+of+protein+utilizing+the+principle+of+protein-dye+binding.">A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding.</a> Analytical Biochemistry. 7 (72), 248-254 (1976).</li><li>Ahmed, N., Argirov, O. K., Minhas, H. S., Cordeiro, C. A., Thornalley, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assay+of+advanced+glycation+endproducts+(AGEs):+surveying+AGEs+by+chromatographic+assay+with+derivatization+by+6-aminoquinolyl-N-hydroxysuccinimidyl-carbamate+and+application+to+Nepsilon-carboxymethyl-lysine-+and+Nepsilon-(1-carboxyethyl)lysine-modified+albumin.">Assay of advanced glycation endproducts (AGEs): surveying AGEs by chromatographic assay with derivatization by 6-aminoquinolyl-N-hydroxysuccinimidyl-carbamate and application to Nepsilon-carboxymethyl-lysine- and Nepsilon-(1-carboxyethyl)lysine-modified albumin.</a> Biochemical Journal. 364 (Pt 1), 1-14 (2002).</li><li>Thornalley, P. J., 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=Quantitative+screening+of+advanced+glycation+endproducts+in+cellular+and+extracellular+proteins+by+tandem+mass+spectrometry.">Quantitative screening of advanced glycation endproducts in cellular and extracellular proteins by tandem mass spectrometry.</a> Biochemical Journal. 375 (Pt 3), 581-592 (2003).</li><li>Karachalias, N., Babaei-Jadidi, R., Ahmed, N., Thornalley, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Accumulation+of+fructosyllysine+and+advanced+glycation+end+products+in+the+kidney,+retina+and+peripheral+nerve+of+streptozotocin-induced+diabetic+rats.">Accumulation of fructosyllysine and advanced glycation end products in the kidney, retina and peripheral nerve of streptozotocin-induced diabetic rats.</a> Biochemical Society Transactions. 31, 1423-1425 (2003).</li><li>Morcos, M., 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=Glyoxalase-1+prevents+mitochondrial+protein+modification+and+enhances+lifespan+in+Caenorhabditis+elegans.">Glyoxalase-1 prevents mitochondrial protein modification and enhances lifespan in Caenorhabditis elegans.</a> Aging Cell. 7 (2), 260-269 (2008).</li><li>Porta-de-la-Riva, M., Fontrodona, L., Villanueva, A., Cer&#243;n, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Basic+Caenorhabditis+elegans+methods:+synchronization+and+observation.">Basic Caenorhabditis elegans methods: synchronization and observation.</a> Journal of Visualized Experiments. (64), e4019 (2012).</li><li>Lagido, C., McLaggan, D., Glover, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Screenable+In+Vivo+Assay+for+Mitochondrial+Modulators+Using+Transgenic+Bioluminescent+Caenorhabditis+elegans.">A Screenable In Vivo Assay for Mitochondrial Modulators Using Transgenic Bioluminescent Caenorhabditis elegans.</a> Journal of Visualized Experiments. (105), e53083 (2015).</li><li>Takamiya, S., Mita, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Large-scale+purification+of+active+liquid-cultured+Caenorhabditis+elegans+using+a+modified+Baermann+apparatus.">Large-scale purification of active liquid-cultured Caenorhabditis elegans using a modified Baermann apparatus.</a> Parasitology International. 65 (5 Pt B), 580-583 (2016).</li><li>Cornaglia, M., Lehnert, T., Gijs, M. A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microfluidic+systems+for+high-throughput+and+high-content+screening+using+the+nematode+Caenorhabditis+elegans.">Microfluidic systems for high-throughput and high-content screening using the nematode Caenorhabditis elegans.</a> Lab Chip. 17 (22), 3736-3759 (2017).</li><li>Zhu, G., Yin, F., Wang, L., Wei, W., Jiang, L., Qin, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modeling+type+2+diabetes-like+hyperglycemia+in+C.+elegans+on+a+microdevice.">Modeling type 2 diabetes-like hyperglycemia in C. elegans on a microdevice.</a> Integrative Biology. 8 (1), 30-38 (2016).</li></ol>

This protocol presents a reliable approach for the large-scale culturing of C. elegans to obtain quantitative results. Findings from the literature could be replicated as shown in the Representative Results. Even though this protocol for the collection of large-scale samples of C. elegans seems like a straight-forward method, there are certain pitfalls to take into account. Regarding the synchronization of the nematode population, this protocol describes an approach by bleaching the pop...

Protein analyses, such as a western blot or mass spectrometry, require milligrams of protein. This yield requires a large-scale culturing of hundreds of C. elegans, which can be accomplished either by liquid culture or on solid media transferring the nematodes by washing. Fluid and shear stress induces the expression of epithelial sodium channels (ENaC), which could increase the osmotic stress through an increased uptake of sodium, potentially altering the lifespan of C. elegans and affecting metabolic analyses1. Therefore, some critical steps in this protocol for the plate-based approach take the reduction of stress affecting experimental variability into account. Liquid culture, on the other hand, influences the phenotype of the nematodes and complicates the culture and collection of an exact number of nematodes2. Moreover, reactive substances can be altered by media components and may distribute unevenly before reaching the nematodes. Regarding the limitations of liquid culture, this protocol provides an alternative approach to culturing large-scale samples of C. elegans.
C. elegans is a model organism with a distinct network of 302 neuronal cells, making up one-third of all its cells3. Since its introduction into science, many homologous and orthologous genes have been described, amplifying its value as a model for medical research. Recently, evidence for neurological impairment in diabetic retinopathy, preceding vascular damage, has been presented4. C. elegans is lacking blood vessels, but contains a distinct neuronal network, making it a suitable model to investigate neuronal alterations apart from vascular ones. Thus, C. elegans is of special interest for studying general mechanisms of diabetic complications. Biochemical alterations in diabetic complications involve the formation of AGEs, which further influence the formation of ROS in response to hyperglycemia5. AGEs are found in C. elegans and contribute to neuronal damage6. Chronic diseases are often caused by complex, polygenic processes requiring a multiparametric approach for the assessment of their underlying mechanisms, as exemplified here with the assessment of diabetic complications. This protocol can be of use for obtaining multiple parameters simultaneously, as well as subsequently. Increased comparability and reproducibility of a multiparametric approach can be achieved by omitting the morphological and metabolic differences between liquid and solid media culture.

<table>
	<tbody>
		<tr>
			<td>E. coli OP50</td>
			<td>CGC</td>
			<td>n/a</td>
			<td></td>
		</tr>
		<tr>
			<td>C. elegans N2</td>
			<td>CGC</td>
			<td>n/a</td>
			<td></td>
		</tr>
		<tr>
			<td>C. elegans CL2166</td>
			<td>CGC</td>
			<td>n/a</td>
			<td></td>
		</tr>
		<tr>
			<td>Petri dish, 60 x 15 mm</td>
			<td>Greiner One</td>
			<td>628161</td>
			<td></td>
		</tr>
		<tr>
			<td>Volumetric pipet, glas, 10 mL</td>
			<td>Neolab</td>
			<td>E-0413</td>
			<td></td>
		</tr>
		<tr>
			<td>Proteinase inhibitor cocktail tablets</td>
			<td>Roche</td>
			<td>04693124001</td>
			<td></td>
		</tr>
		<tr>
			<td>Non-denaturing lysate buffer:</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Tris-HCl, pH 8</td>
			<td>Sigma</td>
			<td>T3253</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodiumchloride (NaCl)</td>
			<td>Sigma</td>
			<td>S7653</td>
			<td></td>
		</tr>
		<tr>
			<td>Triton X-100</td>
			<td>Sigma</td>
			<td>X-100</td>
			<td></td>
		</tr>
		<tr>
			<td>Ethylenediaminetetraacetic acid (EDTA)</td>
			<td>Sigma</td>
			<td>E5391</td>
			<td></td>
		</tr>
		<tr>
			<td>96-well plates, transparent bottom</td>
			<td>Brand</td>
			<td>781611</td>
			<td></td>
		</tr>
		<tr>
			<td>Infinite M200, plate reader</td>
			<td>Tecan</td>
			<td>30017581</td>
			<td></td>
		</tr>
		<tr>
			<td>Zirconium Oxide Beads, 0.5 mm</td>
			<td>Next advance</td>
			<td>ZROB05-RNA</td>
			<td></td>
		</tr>
		<tr>
			<td>Bullet Blender, homogenizer</td>
			<td>Next advance</td>
			<td>BBX24</td>
			<td></td>
		</tr>
		<tr>
			<td>Pepsin from porcine gastric mucosa</td>
			<td>Sigma</td>
			<td>P6887</td>
			<td></td>
		</tr>
		<tr>
			<td>Thymol</td>
			<td>Sigma</td>
			<td>T0501</td>
			<td></td>
		</tr>
		<tr>
			<td>Pronase E/ Protease from Streptomyces griseus </td>
			<td>Sigma</td>
			<td>P6911</td>
			<td></td>
		</tr>
		<tr>
			<td>Penicillin-Streptomycin solution</td>
			<td>Sigma</td>
			<td>P43339</td>
			<td></td>
		</tr>
		<tr>
			<td>Prolidase from Porcine Kidney</td>
			<td>Sigma</td>
			<td>P6675</td>
			<td></td>
		</tr>
		<tr>
			<td>Aminopeptidase from Aeromonas proteolytica</td>
			<td>Sigma</td>
			<td>A8200</td>
			<td></td>
		</tr>
		<tr>
			<td>Amicon Ultra-0.5 Centrifugal Filter Unit</td>
			<td>Merckmillipore</td>
			<td>UFC501096</td>
			<td></td>
		</tr>
		<tr>
			<td>Basic Materials for plate culture are described in Reference 6.</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

plate-based large-scale cultivation of caenorhabditis elegans: sample preparation for the study of metabolic alterations in diabetes

Culturing Caenorhabditis elegans (C. elegans) in a large-scale manner on agar plates can be time-consuming and difficult. This protocol describes a simple and inexpensive method to obtain a large number of animals for the isolation of proteins to proceed with a western blot, mass spectrometry, or further proteomics analyses. Furthermore, an increase of nematode numbers for immunostainings and the integration of multiple analyses under the same culturing conditions can easily be achieved. Additionally, a transfer between plates with different experimental conditions is facilitated. Common techniques in plate culture involve the transfer of a single C. elegans using a platinum wire and the transfer of populated agar chunks using a scalpel. However, with increasing nematode numbers, these techniques become overly time-consuming. This protocol describes the large-scale culture of C. elegans including numerous steps to minimize the impact of the sample preparation on the physiology of the worm. Fluid and shear stress can alter the lifespan of and metabolic processes in C. elegans, thus requiring a detailed description of the critical steps in order to retrieve reliable and reproducible results. C. elegans is a model organism, consisting of neuronal cells for up to one-third, but lacking blood vessels, thus providing the possibility to investigate solely neuronal alterations independent of vascular control. Recently, early neurodegeneration in diabetic retinopathy was found prior to vascular alterations. Thus, C. elegans is of special interest for studying general mechanisms of diabetic complications. For example, an increased formation of advanced glycation end products (AGEs) and reactive oxygen species (ROS) is observed, which are reproducibly found in C. elegans. Protocols to handle samples of adequate size for a broader spectrum of investigations are presented here, exemplified by the study of diabetes-induced biochemical alterations. In general, this protocol can be useful for studies requiring large C. elegans numbers and in which liquid culture is not suitable.

Here examples of creating a large-scale C. elegans culture for applications in diabetes research are presented. It can be of interest to relate the parameters to a single animal, rather than to normalize it to the total protein concentration. In an assay requiring a small number of nematodes, this can be easily accomplished by counting the nematodes. For a large-scale C. elegans culture involving hundreds of nematodes per experimental group, this approach is inconvenient...

Watch this Scientific Journal Video about Plate-based Large-scale Cultivation of Caenorhabditis elegans: Sample Preparation for the Study of Metabolic Alterations in Diabetes at JoVE.com

Plate-based Large-scale Cultivation of Caenorhabditis elegans: Sample Preparation for the Study of Metabolic Alterations in Diabetes

This protocol describes a method for the large-scale cultivation of Caenorhabditis elegans on solid media. As an alternative to liquid culture, this protocol allows obtaining parameters of different scales under plate-based cultivation. This increases the comparability of results by omitting the morphological and metabolic differences between liquid and solid media culture.

Plate-based Large-scale Cultivation of Caenorhabditis elegans: Sample Preparation for the Study of Metabolic Alterations in Diabetes

Culturing Caenorhabditis elegans (C. elegans) in a large-scale manner on agar plates can be time-consuming and difficult. This protocol describes a simple ...

In the C.elegans field, this method can help answer key questions which require the production of large nematode populations and samples using plate culture. The main advantages of this protocol are its easy establishment, and its ease to description, including pitfalls and applications. After obtaining a synchronized population of nematodes, add approximately one milliliter of M nine buffer to the plates, and carefully distribute the buffer by swinging the plates.After this, collect the nematodes in a 15 milliliter tube. Now, invert the tube and use a microscope to evaluate the density of the nematodes. Adjust the density of the suspension as needed, and continue to evaluate it under the microscope.Apply 150 microliters of the suspension directly to the plates with modified pipet tips. To ensure an equal distribution of nematodes between the plates, invert the tube of suspension at regular intervals. First, wash the nematodes using a modified pipet tip with approximately 500 microliters of M nine buffer.Using the same buffer, continue detaching the nematodes until most of the animals are collected in suspension. Next, take up the nematodes with a modified pipet tip, and transfer them to a plate with OP50. The modified pipet tips decrease shear stress and damage to the nematodes because of a larger diameter.Then, allow the plate to dry. Before collecting samples, prepare liquid nitrogen to snap freeze the collected nematodes. Then, place M nine buffer on ice.Apply one milliliter of M nine buffer to each plate, and gently swirl to wash each plate. Then, take up the volume of M nine buffer, and transfer it to new 15 milliliter tubes. Centrifuge the tube briefly at 800 times g, before removing most of the M nine buffer.Next, wash the samples three times with 10 milliliters of M nine buffer to remove any bacteria. Using a glass pipette, transfer each pellet to an empty 1.5 milliliter tube. Use the glass pipette to take up one milliliter of M nine buffer from the second 1.5 milliliter tube, to rinse the nematodes from the pipette wall.Then, wash the remaining nematodes from the 15 milliliter tubes, and transfer them to the sample tubes. Next, centrifuge the sample tubes at 19, 000 times g for one minute, and remove as much supernatant as possible. Then, seal each tube with paraffin film, and snap freeze them in liquid nitrogen immediately.Store the tubes at minus 80 degrees Celsius until lysate preparation. Add the same volumes of 0.5 millimeter zirconium oxide beads, and twice the volume of lysate buffer with proteinase inhibitor cocktail to each frozen sample. Then, place the tubes in a homogenizer for one minute on speed nine.Centrifuge the samples for 30 minutes at four degrees Celsius, and 19, 000 times g. Finally, transfer the supernatant to a new tube on ice, and store it at minus 80 degrees Celsius for future experiments. In this protocol, large quantities of C.elegans were cultured for applications in diabetes research.The number of nematodes collected correlated to the protein yield of the lysate, demonstrating that reproducible quantitative protein isolation can be achieved using this protocol. Mass spectrometric analyses of the reactive metabolite methylglyoxal, and advanced glycation end products formed by methylglyoxal exposure are shown here. Glucose-treated nematodes and controls were compared.Transferring nematodes via pipette can create shear stress, potentially harming the nematodes. Oxidative stress levels in pipetted nematodes and nematodes transferred with a metal wire did not differ using this protocol. Following this procedure, other methods like western blot can be performed, in order to answer additional questions in proteomics.This protocol also facilitates experiments that relate multiple parameters to the same population.

plate-based-large-scale-cultivation-caenorhabditis-elegans-sample

Research

JoVE Journal

Biochemistry

Sample Preparation for Mass Spectrometry-based Identification of RNA-binding Regions

Noncoding RNAs play important roles in several nuclear processes, including regulating gene expression, chromatin structure, and DNA repair. In most cases, the action of noncoding RNAs is mediated by proteins whose functions are in turn regulated by these interactions with noncoding RNAs. Consistent with this, a growing number of proteins involved in nuclear functions have been reported to bind RNA and in a few cases the RNA-binding regions of these proteins have been mapped, often through laborious, candidate-based methods.
Here, we report a detailed protocol to perform a high-throughput, proteome-wide unbiased identification of RNA-binding proteins and their RNA-binding regions. The methodology relies on the incorporation of a photoreactive uridine analog in the cellular RNA, followed by UV-mediated protein-RNA crosslinking, and mass spectrometry analyses to reveal RNA-crosslinked peptides within the proteome. Although we describe the procedure for mouse embryonic stem cells, the protocol should be easily adapted to a variety of cultured cells.

We describe a protocol to identify RNA-binding proteins and map their RNA-binding regions in live cells using UV-mediated photocrosslinking and mass spectrometry.

Noncoding RNAs play important roles in several nuclear processes, including regulating gene expression, chromatin structure, and DNA repair. In most ...

A Simple Method for High Throughput Chemical Screening in Caenorhabditis Elegans

Caenorhabditis elegans is a useful organism for testing chemical effects on physiology. Whole organism small molecule screens offer significant advantages for identifying biologically active chemical structures that can modify complex phenotypes such as lifespan. Described here is a simple protocol for producing hundreds of 96-well culture plates with fairly consistent numbers of C. elegans in each well. Next, we specified how to use these cultures to screen thousands of chemicals for effects on the lifespan of the nematode C. elegans. This protocol makes use of temperature sensitive sterile strains, agar plate conditions, and simple animal handling to facilitate the rapid and high throughput production of synchronized animal cultures for screening.

A Simple Method for High Throughput Chemical Screening in Caenorhabditis Elegans

Here we describe a simple protocol for rapidly producing hundreds of nematode growth media agar, 96-well culture plates with consistent numbers of Caenorhhabditis elegans per well. These cultures are useful for the phenotypic screening of whole organisms. We focus here on using these cultures to screen chemicals for pro-longevity effects.

Caenorhabditis elegans is a useful organism for testing chemical effects on physiology. Whole organism small molecule screens offer significant advantages ...

Small-Scale Colorimetric Assays of Intracellular Lactate and Pyruvate in the Nematode Caenorhabditis elegans

Lactate and pyruvate are key intermediates of intracellular energy metabolic pathways. Monitoring the lactate/pyruvate ratio in cells helps to determine whether there is an imbalance in age-related energy metabolism between mitochondrial oxidative phosphorylation and aerobic glycolysis. Here, we show the utilization of commercial colorimetric assay kits for lactate and pyruvate in the model organism C. elegans. Recently, the sensitivity and accuracy of the colorimetric/fluorimetric assay kits have been improved greatly by the research and development conducted by reagent manufacturers. The improved reagents have enabled the use of small-scale assays with a 96-well plate in C. elegans. In general, a fluorimetric assay is superior in sensitivity to a colorimetric assay; however, the colorimetric approach is more suitable for the use in common laboratories. Another important issue in these assays for quantitative determination is protein precipitation of homogenized C. elegans samples. In our protein precipitation method, common precipitants (e.g., trichloroacetic acid, perchloric acid and metaphosphoric acid) are used for sample preparation. A protein-free assay sample is prepared by directly adding cold precipitant (final concentration of 5%) during homogenization.

Small-Scale Colorimetric Assays of Intracellular Lactate and Pyruvate in the Nematode Caenorhabditis elegans

We describe a modified small-scale extraction and colorimetric assays of lactate and pyruvate in the nematode C. elegans. When utilizing commercial assay kits, the technical development of their sensitivity and accuracy is important. Protein precipitation in extraction is the most critical step for the quantitative determination of intracellular metabolites.

Lactate and pyruvate are key intermediates of intracellular energy metabolic pathways. Monitoring the lactate/pyruvate ratio in cells helps to determine ...

A Colorimetric Assay of Citrate Synthase Activity in Drosophila Melanogaster

Mitochondria play the most prominent roles in cellular metabolism by producing ATP through oxidative phosphorylation and regulating a variety of physiological processes. Mitochondrial dysfunction is a primary cause of a number of metabolic and neurodegenerative diseases. Intact mitochondria are critical for their proper functioning. The enzyme citrate synthase is localized in the mitochondrial matrix and thus can be used as a quantitative enzyme marker of intact mitochondrial mass. Given that many molecules and pathways that have important functions in mitochondria are highly conserved between humans and Drosophila, and that an array of powerful genetic tools are available in Drosophila, Drosophila serves as a good model system for studying mitochondrial function. Here, we present a protocol for fast and simple measurement of citrate synthase activity in tissue homogenate from adult flies without isolating mitochondria. This protocol is also suitable for measuring citrate synthase activity in larvae, cultured cells, and mammalian tissues.

A Colorimetric Assay of Citrate Synthase Activity in Drosophila Melanogaster

We present a protocol for a colorimetric assay of citrate synthase activity for quantification of intact mitochondrial mass in Drosophila tissue homogenates.

Mitochondria play the most prominent roles in cellular metabolism by producing ATP through oxidative phosphorylation and regulating a variety of ...

Synthesis of a Deuterated Standard for the Quantification of 2-Arachidonoylglycerol in Caenorhabditis elegans

This work presents a method to prepare an analytical standard to analyze 2-arachidonoyl glycerol (2-AG) qualitatively and quantitatively by liquid chromatography-electrospray Ionization-tandem mass spectrometry (LC-ESI-MS/MS). Endocannabinoids are conserved lipid mediators that regulate multiple biological processes in a variety of organisms. In C. elegans, 2-AG has been found to possess different roles, including modulation of dauer formation and cholesterol metabolism. This report describes a method to overcome the difficulties associated with the costs and stability of deuterated standards required for 2-AG quantification. The procedure for the synthesis of the standard is simple and can be performed in any laboratory, without the need for organic synthesis expertise or special equipment. In addition, a modification of Folch&#39;s method to extract the deuterated standard from C. elegans culture is described. Finally, a quantitative and analytic method to detect 2-AG using the stable isotopically labeled analog 1-AG-d5 is described, which provides reliable results in a fast-chromatographic run. The procedure is useful for studying the multiple roles of 2-AG in C. elegans while also being applicable to other studies of metabolites in different organisms.

Synthesis of a Deuterated Standard for the Quantification of 2-Arachidonoylglycerol in Caenorhabditis elegans

This work describes a robust and straightforward method to detect and quantify the endocannabinoid 2-arachidonoylglycerol (2-AG) in C. elegans. An analytical deuterated standard us prepared and used for the quantification of 2-AG by isotopic dilution and liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS).

This work presents a method to prepare an analytical standard to analyze 2-arachidonoyl glycerol (2-AG) qualitatively and quantitatively by liquid ...

Medium Preparation for the Cultivation of Microorganisms under Strictly Anaerobic/Anoxic Conditions

In contrast to aerobic organisms, strictly anaerobic microorganisms require the absence of oxygen and usually a low redox potential to initiate growth. As oxygen is ubiquitous in air, retaining O2-free conditions during all steps of cultivation is challenging but a prerequisite for anaerobic culturing. The protocol presented here demonstrates the successful cultivation of an anaerobic mixed culture derived from a biogas plant using a simple and inexpensive method. A precise description of the entire anoxic culturing process is given including media preparation, filling of cultivation flasks, supplementation with redox indicator and reducing agents to provide low redox potentials as well as exchanging the headspace to keep media free from oxygen. Furthermore, a detailed overview of aseptically inoculating gas tight serum flasks (by using sterile syringes and needles) and suitable incubation conditions is provided. The present protocol further deals with gas and liquid sampling for subsequent analyses regarding gas composition and volatile fatty acid concentrations using gas chromatography (GC) and high performance liquid chromatography (HPLC), respectively, and the calculation of biogas and methane yield considering the ideal gas law.

As obligate anaerobic organisms are unable to grow upon oxygen exposure, the use of anaerobic culturing techniques is indispensable. Here, we demonstrate a simple and effective method to cultivate a mixed culture derived from a biogas plant from media preparation to gas and volatile fatty acid quantification.

In contrast to aerobic organisms, strictly anaerobic microorganisms require the absence of oxygen and usually a low redox potential to initiate growth. As ...

Label-Free Immunoprecipitation Mass Spectrometry Workflow for Large-scale Nuclear Interactome Profiling

Immunoaffinity purification mass spectrometry (IP-MS) has emerged as a robust quantitative method of identifying protein-protein interactions. This publication presents a complete interaction proteomics workflow designed for identifying low abundance protein-protein interactions from the nucleus that could also be applied to other subcellular compartments. This workflow includes subcellular fractionation, immunoprecipitation, sample preparation, offline cleanup, single-shot label-free mass spectrometry, and downstream computational analysis and data visualization. Our protocol is optimized for detecting compartmentalized, low abundance interactions that are difficult to identify from whole cell lysates (e.g., transcription factor interactions in the nucleus) by immunoprecipitation of endogenous proteins from fractionated subcellular compartments. The sample preparation pipeline outlined here provides detailed instructions for the preparation of HeLa cell nuclear extract, immunoaffinity purification of endogenous bait protein, and quantitative mass spectrometry analysis. We also discuss methodological considerations for performing large-scale immunoprecipitation in mass spectrometry-based interaction profiling experiments and provide guidelines for evaluating data quality to distinguish true positive protein interactions from nonspecific interactions. This approach is demonstrated here by investigating the nuclear interactome of the CMGC kinase, DYRK1A, a low abundance protein kinase with poorly defined interactions within the nucleus.

Described is a proteomics workflow for identifying protein interaction partners from a nuclear subcellular fraction using immunoaffinity enrichment of a given protein of interest and label-free mass spectrometry. The workflow includes subcellular fractionation, immunoprecipitation, filter aided sample preparation, offline cleanup, mass spectrometry, and a downstream bioinformatics pipeline.

Immunoaffinity purification mass spectrometry (IP-MS) has emerged as a robust quantitative method of identifying protein-protein interactions. This ...

In Vivo Hydroxyl Radical Protein Footprinting for the Study of Protein Interactions in Caenorhabditis elegans

Fast oxidation of proteins (FPOP) is a hydroxyl radical protein footprinting (HRPF) method used to study protein structure, protein-ligand interactions, and protein-protein interactions. FPOP utilizes a KrF excimer laser at 248 nm for photolysis of hydrogen peroxide to generate hydroxyl radicals which in turn oxidatively modify solvent-accessible amino acid side chains. Recently, we expanded the use of FPOP of in vivo oxidative labeling in Caenorhabditis elegans (C. elegans), entitled IV-FPOP. The transparent nematodes have been used as model systems for many human diseases. Structural studies in C. elegans by IV-FPOP is feasible because of the animal&#8217;s ability to uptake hydrogen peroxide, their transparency to laser irradiation at 248 nm, and the irreversible nature of the modification. The assembly of a microfluidic flow system for IV-FPOP labeling, IV-FPOP parameters, protein extraction, and LC-MS/MS optimized parameters are described herein.

In Vivo Hydroxyl Radical Protein Footprinting for the Study of Protein Interactions in Caenorhabditis elegans

In vivo fast photochemical oxidation of proteins (IV-FPOP) is a hydroxyl radical protein footprinting technique that allows for mapping of protein structure in their native environment. This protocol describes the assembly and set-up of the IV-FPOP microfluidic flow system.

Fast oxidation of proteins (FPOP) is a hydroxyl radical protein footprinting (HRPF) method used to study protein structure, protein-ligand interactions, ...

Isolation of Active Caenorhabditis elegans Nuclear Extract and Reconstitution for In Vitro Transcription

Caenorhabditis elegans has been an important model system for biological research since it was introduced in 1963. However, C. elegans has not been fully utilized in the biochemical study of biological reactions using its nuclear extracts such as in vitro transcription and DNA replication. A significant hurdle for using C. elegans in biochemical studies is disrupting the nematode&#39;s thick outer cuticle without sacrificing the activity of the nuclear extract. While several methods are used to break the cuticle, such as Dounce homogenization or sonication, they often lead to protein instability. There are no established protocols for isolating active nuclear proteins from larva or adult C. elegans for in vitro reactions. Here, the protocol describes in detail the homogenization of larval stage 4 C. elegans using a Balch homogenizer. The Balch homogenizer uses pressure to slowly force the animals through a narrow gap breaking the cuticle in the process. The uniform design and precise machining of the Balch homogenizer allow for consistent grinding of animals between experiments. Fractionating the homogenate obtained from the Balch homogenizer yields functionally active nuclear extract that can be used in an in vitro method for assaying transcription activity of C. elegans.

Isolation of Active Caenorhabditis elegans Nuclear Extract and Reconstitution for In Vitro Transcription

Here, we describe a detailed protocol for isolating active nuclear extract from larval stage 4 C. elegans and visualizing transcription activity in an in vitro system.

Caenorhabditis elegans has been an important model system for biological research since it was introduced in 1963. However, C. elegans has not been fully ...

Large-Scale Multi-Omics Genome-Wide Association Studies (Mo-GWAS): Guidelines for Sample Preparation and Normalization

Both gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) are widely used metabolomics approaches to detect and quantify hundreds of thousands of metabolite features. However, the application of these techniques to a large number of samples is subject to more complex interactions, particularly for genome-wide association studies (GWAS). This protocol describes an optimized metabolic workflow, which combines an efficient and fast sample preparation with the analysis of a large number of samples for legume crop species. This slightly modified extraction method was initially developed for the analysis of plant and animal tissues and is based on extraction in methyl tert-butyl ether: methanol solvent to allow the capture of polar and lipid metabolites. In addition, we provide a step-by-step guide for reducing analytical variations, which are essential for the high-throughput evaluation of metabolic variance in GWAS.

Large-Scale Multi-Omics Genome-Wide Association Studies Mo-GWAS: Guidelines for Sample Preparation and Normalization

In this protocol, we present an optimized workflow, which combines an efficient and fast sample preparation of many samples. In addition, we provide a step-by-step guide to reduce analytical variations for high-throughput evaluation of metabolic GWAS studies.

Both gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) are widely used metabolomics approaches to detect ...