Name: sample preparation for rapid lipid analysis in drosophila brain using matrix-assisted laser desorption/ionization mass spectrometry imaging
Uploaded: 2022-07-14T14:00:00
Description: Watch this Scientific Journal Video about Sample Preparation for Rapid Lipid Analysis in Drosophila Brain Using Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging at JoVE.com

Yuki X. Chen, Kelly Veerasammy, and Mayan Hein are supported by the Sloan Foundation CUNY Summer Research Program (CSURP). Jun Yin is supported by the intramural research program of the National Institutes of Health Project Number 1ZIANS003137. Support for this project was provided by a PSC-CUNY Award to Ye He and Rinat Abzalimov, jointly funded by The Professional Staff Congress and The City University of New York.

1. Fly head embedding
NOTE: The whole procedure takes ~45-60 min.
<ol>
	<li>Prepare the optimal cutting temperature compound (OCT compound) stage with a flat surface.
	<ol>
		<li>Add OCT into a plastic cryomold (15 mm x 15 mm x 5 mm) to half of the depth of the cryomold and avoid bubble formation. Leave the mold on a flat surface for several minutes, and then transfer it onto dry ice.</li>
		<li>Keep the cryomold flat on the dry ice and allow the OCT to form a flat and even ...

<ol>
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Part I: Modern lipid analysis.</a> TrAC Trends in Analytical Chemistry. 28 (3), 263-278 (2009).</li><li>Navas-Iglesias, N., Carrasco-Pancorbo, A., Cuadros-Rodriguez, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=From+lipids+analysis+towards+lipidomics,+a+new+challenge+for+the+analytical+chemistry+of+the+21st+century.+Part+II:+Analytical+lipidomics.">From lipids analysis towards lipidomics, a new challenge for the analytical chemistry of the 21st century. Part II: Analytical lipidomics.</a> TrAC Trends in Analytical Chemistry. 28 (4), 393-403 (2009).</li><li>Yang, K., Han, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lipidomics:+Techniques,+applications,+and+outcomes+related+to+biomedical+sciences.">Lipidomics: Techniques, applications, and outcomes related to biomedical sciences.</a> Trends in Biochemical Sciences. 41 (11), 954-969 (2016).</li><li>Norris, J. L., Caprioli, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+tissue+specimens+by+matrix-assisted+laser+desorption/ionization+imaging+mass+spectrometry+in+biological+and+clinical+research.">Analysis of tissue specimens by matrix-assisted laser desorption/ionization imaging mass spectrometry in biological and clinical research.</a> Chemical Reviews. 113 (4), 2309-2342 (2013).</li><li>Veerasammy, 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=Sample+preparation+for+metabolic+profiling+using+MALDI+mass+spectrometry+imaging.">Sample preparation for metabolic profiling using MALDI mass spectrometry imaging.</a> Journal of Visualized Experiments. (166), e62008 (2020).</li><li>Tracey, T. J., Steyn, F. J., Wolvetang, E. J., Ngo, S. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuronal+lipid+metabolism:+Multiple+pathways+driving+functional+outcomes+in+health+and+disease.">Neuronal lipid metabolism: Multiple pathways driving functional outcomes in health and disease.</a> Frontiers in Molecular Neuroscience. 11, 10 (2018).</li><li>Jackson, C. L., Walch, L., Verbavatz, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lipids+and+their+trafficking:+An+integral+part+of+cellular+organization.">Lipids and their trafficking: An integral part of cellular organization.</a> Developmental Cell. 39 (2), 139-153 (2016).</li><li>Wang, H., Eckel, R. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=What+are+lipoproteins+doing+in+the+brain.">What are lipoproteins doing in the brain.</a> Trends in Endocrinology and Metabolism. 25 (1), 8-14 (2014).</li><li>Palm, W., 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=Lipoproteins+in+Drosophila+melanogaster-Assembly,+function,+and+influence+on+tissue+lipid+composition.">Lipoproteins in Drosophila melanogaster-Assembly, function, and influence on tissue lipid composition.</a> PLoS Genetics. 8 (7), 1002828 (2012).</li><li>Parra-Peralbo, E., Culi, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Drosophila+lipophorin+receptors+mediate+the+uptake+of+neutral+lipids+in+oocytes+and+imaginal+disc+cells+by+an+endocytosis-independent+mechanism.">Drosophila lipophorin receptors mediate the uptake of neutral lipids in oocytes and imaginal disc cells by an endocytosis-independent mechanism.</a> PLoS Genetics. 7 (2), 1001297 (2011).</li><li>Yin, 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=Brain-specific+lipoprotein+receptors+interact+with+astrocyte+derived+apolipoprotein+and+mediate+neuron-glia+lipid+shuttling.">Brain-specific lipoprotein receptors interact with astrocyte derived apolipoprotein and mediate neuron-glia lipid shuttling.</a> Nature Communications. 12 (1), 2408 (2021).</li><li>Tuthill, B. F., Searcy, L. A., Yost, R. A., Musselman, L. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tissue-specific+analysis+of+lipid+species+in+Drosophila+during+overnutrition+by+UHPLC-MS/MS+and+MALDI-MSI.">Tissue-specific analysis of lipid species in Drosophila during overnutrition by UHPLC-MS/MS and MALDI-MSI.</a> Journal of Lipid Research. 61 (3), 275-290 (2020).</li><li>Kaya, I., Jennische, E., Lange, S., Malmberg, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multimodal+chemical+imaging+of+a+single+brain+tissue+section+using+ToF-SIMS,+MALDI-ToF+and+immuno/histochemical+staining.">Multimodal chemical imaging of a single brain tissue section using ToF-SIMS, MALDI-ToF and immuno/histochemical staining.</a> Analyst. 146 (4), 1169-1177 (2021).</li><li>Phan, N. T., Fletcher, J. S., Ewing, A. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lipid+structural+effects+of+oral+administration+of+methylphenidate+in+Drosophila+brain+by+secondary+ion+mass+spectrometry+imaging.">Lipid structural effects of oral administration of methylphenidate in Drosophila brain by secondary ion mass spectrometry imaging.</a> Analytical Chemistry. 87 (8), 4063-4071 (2015).</li><li>Dienel, G. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Metabolomic+and+imaging+mass+spectrometric+assays+of+labile+brain+metabolites:+Critical+importance+of+brain+harvest+procedures.">Metabolomic and imaging mass spectrometric assays of labile brain metabolites: Critical importance of brain harvest procedures.</a> Neurochemical Research. 45 (11), 2586-2606 (2020).</li><li>Schwartz, S. A., Reyzer, M. L., Caprioli, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Direct+tissue+analysis+using+matrix-assisted+laser+desorption/ionization+mass+spectrometry:+Practical+aspects+of+sample+preparation.">Direct tissue analysis using matrix-assisted laser desorption/ionization mass spectrometry: Practical aspects of sample preparation.</a> Journal of Mass Spectrometry. 38 (7), 699-708 (2003).</li><li>Phan, N. T., Mohammadi, A. S., Dowlatshahi Pour, M., Ewing, A. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laser+desorption+ionization+mass+spectrometry+imaging+of+Drosophila+brain+using+matrix+sublimation+versus+modification+with+nanoparticles.">Laser desorption ionization mass spectrometry imaging of Drosophila brain using matrix sublimation versus modification with nanoparticles.</a> Analytical Chemistry. 88 (3), 1734-1741 (2016).</li><li>Niehoff, A. C., 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=Analysis+of+Drosophila+lipids+by+matrix-assisted+laser+desorption/ionization+mass+spectrometric+imaging.">Analysis of Drosophila lipids by matrix-assisted laser desorption/ionization mass spectrometric imaging.</a> Analytical Chemistry. 86 (22), 11086-11092 (2014).</li><li>Enomoto, Y., Nt An, P., Yamaguchi, M., Fukusaki, E., Shimma, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mass+spectrometric+imaging+of+GABA+in+the+Drosophila+melanogaster+adult+head.">Mass spectrometric imaging of GABA in the Drosophila melanogaster adult head.</a> Analytical Sciences. 34 (9), 1055-1059 (2018).</li><li>Yang, E., Gamberi, C., Chaurand, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mapping+the+fly+malpighian+tubule+lipidome+by+imaging+mass+spectrometry.">Mapping the fly malpighian tubule lipidome by imaging mass spectrometry.</a> Journal of Mass Spectrometry. 54 (6), 557-566 (2019).</li><li>Blanksby, S. J., Mitchell, T. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Advances+in+mass+spectrometry+for+lipidomics.">Advances in mass spectrometry for lipidomics.</a> Annual Review of Analytical Chemistry. 3, 433-465 (2010).</li><li>Han, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lipidomics+for+studying+metabolism.">Lipidomics for studying metabolism.</a> Nature Reviews Endocrinology. 12 (11), 668-679 (2016).</li><li>Wang, M., Wang, C., Han, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Selection+of+internal+standards+for+accurate+quantification+of+complex+lipid+species+in+biological+extracts+by+electrospray+ionization+mass+spectrometry-What,+how+and+why.">Selection of internal standards for accurate quantification of complex lipid species in biological extracts by electrospray ionization mass spectrometry-What, how and why.</a> Mass Spectrometry Reviews. 36 (6), 693-714 (2017).</li></ol>

As demonstrated in the study on the variations in lipid composition in mutant and wild-type Drosophila brains, MALDI MSI can be a valuable label-free imaging technique for in situ analysis of molecular distribution patterns within organs of small insects. Indeed, because lipids are distributed in both the brain tissue and fat bodies of Drosophila heads, conventional lipidomics approaches based on liquid-chromatography and mass-spectrometry (LC-MS) can detect only combined signals from both regi...

Lipids are involved in a wide range of biological processes and can be broadly classified into five categories based on their structural diversity: fatty acids, triacylglycerols (TAGs), phospholipids, sterol lipids, and sphingolipids1. The fundamental functions of lipids are to provide energy sources for biological processes (i.e., TAGs) and form cellular membranes (i.e., phospholipids and cholesterol).&#160;However, additional roles of lipids have been noted in development and diseases, and have been extensively studied in the biomedical field. For instance, reports have shown that fatty acids of different lengths may have unique therapeutic roles. Short fatty acid chains can be involved in defense mechanisms against autoimmune diseases, medium-length fatty acid chains produce metabolites that can mitigate seizures, and long fatty acid chains generate metabolites that can be used to treat metabolic disorders2. In the nervous system, glia-derived cholesterol and phospholipids have been shown to be vital for synaptogenesis3,4. Other types of lipids have shown promise in medical applications, including&#160;sphingolipids utilized in drug delivery systems and saccharolipids&#160;used to support the immune system5,6. The numerous roles and potential therapeutic applications of lipids in the biomedical field have made lipidomics&#8212;the study of the pathways and interactions of cellular lipids&#8212;a critical and increasingly important field.
Lipidomics makes use of analytical chemistry to study the lipidome on a large scale. The main experimental methods utilized in lipidomics are based on mass spectrometry (MS) coupled with various chromatography and ion-mobility techniques7,8. The use of MS in the area is advantageous due to its high specificity and sensitivity, speed of acquisition, and unique capabilities to (1) detect lipids and lipid metabolites occurring even at low and transient levels, (2) detect hundreds of different lipid compounds in a single experiment, (3) identify previously unknown lipids, and (4) distinguish between lipid isomers. Among the developments in MS, including desorption electrospray ionization (DESI), MALDI, and secondary ion mass spectrometry (SIMS), MALDI MSI has emerged as a powerful imaging technique that complements conventional MS-based approaches by providing unique information on the spatial distribution of lipids within tissue compartments9,10.
The typical workflow of lipidomics consists of sample preparation, data acquisition using mass-spectrometry technology, and data analysis11. The study of lipids and metabolites in samples has led to the emergence of techniques to understand the physiological and pathological conditions of metabolic processes in organisms. While understanding biological interactions is important, the sensitivity of lipids and metabolites makes them difficult to image and identify without dyes or other modification. Changes in metabolite levels or distribution may lead to phenotypic changes. One tool used for metabolomic profiling is MALDI MSI, a label-free, in situ imaging technique capable of detecting hundreds of molecules simultaneously. MALDI imaging allows for the visualization of metabolites and lipids in samples while preserving their integrity and spatial distribution. Previous technology for lipid profiling involved the use of radioactive chemicals to individually map lipids, while MALDI imaging forgoes this and allows for the detection of a range of lipids simultaneously.
Lipid metabolism and homeostasis play important functions in cell physiology, such as the maintenance and development of the nervous system. One essential aspect of nervous system lipid metabolism is the lipid shuttling between neurons and glial cells, which is mediated by molecular carrier lipoproteins, including very-low-density lipoprotein (VLDL), low-density lipoproteins (LDL), and high-density lipoproteins (HDL)12. Lipoproteins contain apolipoproteins (Apo), such as ApoB and ApoD, which function as structural blocks of lipid cargo and as ligands for lipoprotein receptors. The neuron-glia crosstalk of lipids involves multiple players such as glia-derived ApoD, ApoE, and ApoJ, and their neuronal LDL receptors (LDLRs)13,14. In Drosophila, apolipophorin, a member of the ApoB family, is a major hemolymph lipid carrier15. Apolipophorin has two closely related lipophorin receptors (LpRs), LpR1 and LpR2, which are homologs of mammalian LDLR15,16. In previous studies, the astrocyte-secreted lipocalin Glial Lazarillo (GLaz), a Drosophila homolog of human ApoD, and its neuronal receptor LpR1 were discovered to cooperatively mediate neuron-glia lipid shuttling, thus regulating dendrite morphogenesis17. Therefore, it was speculated that the loss of LpR1 would cause a decrease in overall lipid content in the Drosophila brain. MALDI MSI would be a suitable tool for profiling the lipid contents in small tissues of LpR1&#8722;/&#8722; mutant and wild-type Drosophila brains, as demonstrated in this study.
Despite the growing popularity of MALDI MSI, the instrument&#39;s high cost and experimental complexity often impede its implementation in individual laboratories. Thus, most MALDI MSI studies are conducted using shared core facilities. As with other applications of MALDI MSI, a careful sample preparation process for lipidomics is critical to achieve reliable results. However, because sample slide preparation is typically performed in individual research laboratories, there is a possibility of variation in MALDI MSI acquisition. To combat this, this paper aims to provide a detailed protocol for the sample preparation of small biological samples prior to MALDI MSI measurement using lipid analysis of a large group of adult Drosophila brains in positive ion mode as an example11,17. However, some phospholipid classes and the majority of small metabolites are favorably detected by MALDI imaging in negative ion mode, which was described previously11. Therefore, with these two example studies, we hope to provide detailed sample preparation protocols of various combinations: free-standing large tissue versus embedded small tissue, thaw-mounting versus warm-slide mounting, and positive ion mode versus negative ion mode.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>2,5-Dihydroxybenzoic acid (DHB)</td>
			<td>Millipore Sigma Aldrich</td>
			<td>85707-1G-F</td>
			<td></td>
		</tr>
		<tr>
			<td>Andwin Scientific&#160;CRYOMOLD 15X15X5</td>
			<td>Fisher Scientific</td>
			<td>NC9464347</td>
			<td></td>
		</tr>
		<tr>
			<td>Andwin Scientific&#160;Tissue-Tek CRYO-OCT Compound</td>
			<td>Fisher Scientific</td>
			<td>14-373-65</td>
			<td></td>
		</tr>
		<tr>
			<td>Artist brush MSC #5 1/8 X 9/16 TRIM RED SABLE</td>
			<td>Fisher Scientific</td>
			<td>50-111-2302</td>
			<td></td>
		</tr>
		<tr>
			<td>autoflex speed MALDI-TOF MS system</td>
			<td>Bruker Daltonics Inc</td>
			<td></td>
			<td>MALDI-TOF MS instrument</td>
		</tr>
		<tr>
			<td>BD&#160;Syringe with Luer-Lok Tips</td>
			<td>Fisher Scientific</td>
			<td>14-823-16E</td>
			<td></td>
		</tr>
		<tr>
			<td>BD&#160;Vacutainer General Use Syringe Needles</td>
			<td>Fisher Scientific</td>
			<td>23-021-020</td>
			<td></td>
		</tr>
		<tr>
			<td>Bruker Daltonics&#160;GLASS SLIDES MALDI IMAGNG</td>
			<td>Fisher Scientific</td>
			<td>NC0380464</td>
			<td></td>
		</tr>
		<tr>
			<td>Drierite, with indicator, 8 mesh, ACROS Organics</td>
			<td></td>
			<td>AC219095000</td>
			<td></td>
		</tr>
		<tr>
			<td>Epson Perfection V600 Photo Scanner</td>
			<td>Amazon</td>
			<td>Perfection V600</td>
			<td></td>
		</tr>
		<tr>
			<td>Fisherbrand&#160;5-Place Slide Mailer</td>
			<td>Fisher Scientific</td>
			<td>HS15986</td>
			<td></td>
		</tr>
		<tr>
			<td>Fisherbrand&#160;Digital Auto-Range Multimeter</td>
			<td>Fisher Scientific</td>
			<td>01-241-1</td>
			<td></td>
		</tr>
		<tr>
			<td>FlexImaging v3.0</td>
			<td>Bruker Daltonics Inc</td>
			<td></td>
			<td>Bruker MS imaging analysis software</td>
		</tr>
		<tr>
			<td>HPLC Grade Methanol</td>
			<td>Fisher Scientific</td>
			<td>MMX04751</td>
			<td></td>
		</tr>
		<tr>
			<td>HPLC Grade Water</td>
			<td>Fisher Scientific</td>
			<td>W5-1</td>
			<td></td>
		</tr>
		<tr>
			<td>HTX M5 Sprayer</td>
			<td>HTX Technologies, LLC</td>
			<td></td>
			<td>Automatic heated matrix sprayer</td>
		</tr>
		<tr>
			<td>Kimberly-Clark Professional&#160;Kimtech Science Kimwipes Delicate Task Wipers</td>
			<td>Fisher Scientific</td>
			<td>06-666A</td>
			<td></td>
		</tr>
		<tr>
			<td>MSC&#160;Ziploc Freezer Bag</td>
			<td>Fisher Scientific</td>
			<td>50-111-3769</td>
			<td></td>
		</tr>
		<tr>
			<td>SCiLS Lab (2015b)</td>
			<td>SCiLS Lab</td>
			<td></td>
			<td>Advanced MALDI MSI data analysis software</td>
		</tr>
		<tr>
			<td>Thermo Scientific&#160;CryoStar NX50 Cryostat</td>
			<td>Fisher Thermo Scientific</td>
			<td>95-713-0</td>
			<td></td>
		</tr>
		<tr>
			<td>Thermo Scientific&#160;Nalgene Transparent Polycarbonate Classic Design Desiccator</td>
			<td>Fisher Scientific</td>
			<td>08-642-7</td>
			<td></td>
		</tr>
	</tbody>
</table>

sample preparation for rapid lipid analysis in drosophila brain using matrix-assisted laser desorption/ionization mass spectrometry imaging

Lipid profiling, or lipidomics, is a well-established technique used to study the entire lipid content of a cell or tissue. Information acquired from&#160;lipidomics is valuable in studying the pathways involved in development, disease, and cellular metabolism. Many tools and instrumentations have aided lipidomics projects, most notably various combinations of mass spectrometry and liquid chromatography techniques. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) has recently emerged as a powerful imaging technique that complements conventional approaches. This novel technique provides unique information on the spatial distribution of lipids within tissue compartments, which was previously unattainable without the use of excessive modifications. The sample preparation of the MALDI MSI approach is critical and, therefore, is the focus of this paper. This paper presents a rapid lipid analysis of a large number of Drosophila brains embedded in optimal cutting temperature compound (OCT) to provide a detailed protocol for the preparation of small tissues for lipid analysis or metabolite and small molecule analysis through MALDI MSI.

The loss of the neuronal receptor LpR1 of the astrocyte-secreted lipocalin Glial Lazarillo (GLaz), a Drosophila homolog of human ApoD, was hypothesized to be able to cause a decrease in overall lipid content in the Drosophila brain. To test this, MALDI MSI was used to profile the lipids in LpR1&#8722;/&#8722; mutant and wild-type Drosophila brains, which is elaborated on below.
The experiment was performed according to the workflow shown in <stron...

Watch this Scientific Journal Video about Sample Preparation for Rapid Lipid Analysis in Drosophila Brain Using Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging at JoVE.com

Sample Preparation for Rapid Lipid Analysis in Drosophila Brain Using Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging

The aim of this protocol is to provide detailed guidance on the proper sample preparation for lipid and metabolite analysis in small tissues, such as the Drosophila brain, using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging.

Sample Preparation for Rapid Lipid Analysis in Drosophila Brain Using Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging

Lipid profiling, or lipidomics, is a well-established technique used to study the entire lipid content of a cell or tissue. Information acquired ...

Research

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Biology

MALDI Sample Preparation: the Ultra Thin Layer Method

This video demonstrates the preparation of an ultra-thin matrix/analyte layer for analyzing peptides and proteins by Matrix-Assisted Laser Desorption ...

The Preparation of Drosophila Embryos for Live-Imaging Using the Hanging Drop Protocol

The Preparation of Drosophila Embryos for Live-Imaging Using the Hanging Drop Protocol

Green fluorescent protein (GFP)-based timelapse live-imaging is a powerful technique for studying the genetic regulation of dynamic processes such as ...

Profiling Thiol Redox Proteome Using Isotope Tagging Mass Spectrometry

Pseudomonas syringae pv. tomato strain DC3000 not only causes bacterial speck disease in Solanum lycopersicum but also on Brassica species, as well as on ...

Dithranol as a Matrix for Matrix Assisted Laser Desorption/Ionization Imaging on a Fourier Transform Ion Cyclotron Resonance Mass Spectrometer

Mass spectrometry imaging (MSI) determines the spatial localization and distribution patterns of compounds on the surface of a tissue section, mainly ...

Rapid Analysis and Exploration of Fluorescence Microscopy Images

Despite rapid advances in high-throughput microscopy, quantitative image-based assays still pose significant challenges. While a variety of specialized ...

Complete Workflow for Analysis of Histone Post-translational Modifications Using Bottom-up Mass Spectrometry: From Histone Extraction to Data Analysis

Nucleosomes are the smallest structural unit of chromatin, composed of 147 base pairs of DNA wrapped around an octamer of histone proteins. Histone ...

Sample Preparation for Mass Cytometry Analysis

Mass cytometry utilizes antibodies conjugated with heavy metal labels, an approach that has greatly increased the number of parameters and opportunities ...

Sample Preparation and Imaging of Exosomes by Transmission Electron Microscopy

Exosomes are nano-sized extracellular vesicles secreted by body fluids and are known to represent the characteristics of cells that secrete them. The ...

Miniaturized Sample Preparation for Transmission Electron Microscopy

Due to recent technological progress, cryo-electron microscopy (cryo-EM) is rapidly becoming a standard method for the structural analysis of protein ...

Measurement of Energy Metabolism in Explanted Retinal Tissue Using Extracellular Flux Analysis

High acuity vision is a heavily energy-consuming process, and the retina has developed several unique adaptations to precisely meet such demands while ...