Nous remercions le Professeur Eichele de nous avoir permis d&#39;utiliser la cryo-microtome. Le travail a été financé par Max-Planck-Gesselschaft.

1. Préparation <ol><li> Fraîchement préparer fixateur de Carnoy, en combinant l&#39;éthanol absolu, le chloroforme et l&#39;acide acétique glacial en proportion 06:03:01 respectivement. 3 Ceci, ainsi que toutes les solutions pour cols submergeant devraient être conservés dans des bocaux en verre coloration (voir la section des réactifs pour la recommandation). </li><li> Préparer une feuille d&#39;aluminium poches de la taille correcte pour les colliers. </li><li> Préparer les solutions suivantes dans la coloration des pots: 2 X 40% d&#39;éthanol, 70% d&#39;éthanol, l&#39;éthanol 2 X 100%, méthylbenzoate (Mo), 50/50 v / v Mo et la paraffine, la paraffine X 2. Placez le MB et les conteneurs de paraffine dans un incubateur réglé à 60-65 ° C. </li><li> Paraffine chaude pour verser dans les poches aluminium à 60-65 ° C. </li></ol> 2. Fixation mouches dans Colliers <ol><li> Fixez le collier 4 sous la loupe binoculaire à l&#39;aide de bandes en position verticale où vous pouvez voir le point d&#39;entrée pour le voler. </li><li> Anesthetize mouches avec du dioxyde de carbone ou via l&#39;hypothermie en utilisant un bloc de glace. Soyez prudent de ne pas geler les mouches. </li><li> En utilisant des pinces, ramasser des mouches individuels en saisissant leurs ailes et les placer dans le col correctement orienté (tête et thorax au-dessus des lames et l&#39;abdomen, sous les lames). 10-20 mouches devraient facilement dans le col. </li></ol> Remarque: Si vous analysez plusieurs génotypes, n&#39;oubliez pas de faire une note du numéro de collier et le génotype correspondant. 3. Coupes de paraffine de thorax drosophile <ol><li> Relocaliser le col à la solution du Carnoy et fixer le tissu à 4 ° C pendant la nuit. </li><li> Après fixation, déshydrater l&#39;échantillon en utilisant des concentrations croissantes d&#39;éthanol. Pour 10 minutes chacune plonger le col dans 40% (2 fois), 70% et 100% (2 fois) d&#39;éthanol à température ambiante. Suivant cols incuber dans une solution de Mo et Mo de paraffine + (1:1) pendant 30 min dans chaque puis infiltrer le col en deux changements de paraffine pour 60 min chacun à 60-65 ° C. Rapidement déplacer le collier dans la poche d&#39;aluminium et remplir de fondu (60-65 ° C) de paraffine. Placez-le à température ambiante et permettre à la paraffine pour devenir dur (il est préférable de laisser toute la nuit). Notez que le collier peut être placé dans la poche une feuille dans différentes orientations, en fonction de l&#39;orientation des sections dont vous avez besoin (longitudinale ou transversale). </li><li> Déballer les blocs de paraffine sèche avec des colliers de la feuille et délicatement séparer le collier de son bloc de paraffine. Avec l&#39;aide d&#39;une lame tranchante ou d&#39;un scalpel découpez soigneusement la paraffine extra-partir autour du tissu volée. </li><li> Couper le bloc de paraffine à 7-10 étapes section pm sur un microtome de rotation et de permettre le tissu coupé pour flotter à plat dans un bain à 37 ° C l&#39;eau. Placer le tissu sectionnée sur les lames polaires et laisser sécher pendant la nuit. Ces diapositives peuvent être utilisées pour la coloration avec hématoxyline et l&#39;éosine (figure 1A-D), le bleu de toluidine, le bleu d&#39;aniline ou décède d&#39;autres de visualiser les structures des tissus, ainsi que pour la coloration des anticorps (figure 1E-E ``). </li></ol> 4. Cryocoupes du thorax chez la drosophile <ol><li> Comme avec des sections de paraffine, de préparer les mouches dans un collier et de la mode d&#39;une poche d&#39;aluminium. Un refroidisseur de gel seront nécessaires pour préparer les échantillons. Assurez-vous que le refroidisseur est autour de -60 ° C, utilisez un peu d&#39;éthanol et de glace sèche pour permettre d&#39;atteindre cette température. Une heure avant de commencer l&#39;expérience mettre la bouteille de milieu cryo-intégration (Tissue-Tek octobre composés) à l&#39;envers dans un réfrigérateur à 4 ° C afin de le refroidir et de minimiser la formation de bulles d&#39;air. </li><li> Relocaliser le col avec des mouches à la poche une feuille qui a été pré-refroidi pendant plusieurs minutes à l&#39;intérieur du refroidisseur de congélation et de combler rapidement avec le composé cryo-enrobage. Laissez le gel de l&#39;échantillon pendant 3-10 min. Soigneusement déballer le bloc formé à l&#39;intérieur du refroidisseur, délicatement séparés le col du bloc de l&#39;incorporation et le mettre à -20 ° C pendant au moins un jour. </li><li> Coupez les muscles gelés sur un cryo-microtome entre -15 et -18 ° C avec une épaisseur de coupe de 10-15 um. Placer sur des lames polarisée et la garder au -20 ° C jusqu&#39;au moment de faire un traitement ultérieur. Nous vous suggérons de fixer les tissus dans le formol solution à 4% du PBS pendant 10 min à température ambiante avant la coloration des anticorps. </li></ol> 5. Détection des lipides dans les muscles chez la drosophile Gouttelettes lipidiques peuvent être détectés avec de l&#39;huile rouge O tache sur cryocoupes utilisant un protocole adopté par Sieber et Thummel 5. <ol><li> Après fixation, laver les lames avec de l&#39;eau deux fois pendant 5 min, équilibrée dans du propylène glycol pendant 10 min et laisser incuber pendant 3 h dans de l&#39;huile rouge O tache à température ambiante. Puis laver les échantillons 2 fois pendant 5 min dans du propylène glycol et 30 min dans du PBS. Mont de glycérol 30%. </li></ol> 6. Les résultats représentatifs: <img src="/files/ftp_upload/2438/2438fig1.jpg" alt="Figure 1" /> FigUre 1. Paraffine-incorporés sections Hématoxyline éosine et colorées transversale (AB) et longitudinale (CD) des sections de muscles de vol indirect. A et C montre normale muscles structurés. Anormale par les muscles taille et la morphologie sont représentés sur B et D, respectivement (flèches noires). Coupe transversale de thorax tachés drosophile avec des anti-LAMC, marqueur de l&#39;enveloppe nucléaire et le DAPI, colorant nucléaire (EF). Vue agrandie de la normale (flèche rouge) et se sont détériorées (flèche jaune) des muscles (F). G représente la section du vitrail drosophile intestinal avec LAMC et DAPI. <img src="/files/ftp_upload/2438/2438fig2.jpg" alt="Figure 2" /> Figure 2. Des sections congelées A. Les sections transversales congelés de vitraux du thorax chez la drosophile à l&#39;huile rouge O, lipides gouttelettes étiquette. B. longitudinale des coupes congelées de muscles vol indirect teinté d&#39;anti-Dg, le muscle sarcolemme marqueur et DAPI.

<ol>
	<li>Miller, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+internal+anatomy+and+histology+of+the+imago+of+Drosophila+melanogaster.">The internal anatomy and histology of the imago of Drosophila melanogaster.</a> , (1950).</li><li>Shcherbata, H. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dissecting+muscle+and+neuronal+disorders+in+a+Drosophila+model+of+muscular+dystrophy.">Dissecting muscle and neuronal disorders in a Drosophila model of muscular dystrophy.</a> The EMBO journal. 26, 481-481 (2007).</li><li>Kucherenko, 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=Genetic+modifier+screens+reveal+new+components+that+interact+with+the+Drosophila+dystroglycan-dystrophin+complex.">Genetic modifier screens reveal new components that interact with the Drosophila dystroglycan-dystrophin complex.</a> PloS one. 3, e2418-e2418 (2008).</li><li>Puchtler, H., Waldrop, F. S., Conner, H. M., Terry, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Carnoy+fixation:+practical+and+theoretical+considerations.">Carnoy fixation: practical and theoretical considerations.</a> Histochemie. 16, 361-36 (1968).</li><li>Ashburner, 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> Drosophila - A Laboratory Manual. , (1989).</li><li>Sieber, M. H., Thummel, C. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+DHR96+nuclear+receptor+controls+triacylglycerol+homeostasis+in+Drosophila.">The DHR96 nuclear receptor controls triacylglycerol homeostasis in Drosophila.</a> Cell metabolism. 10, 481-481 (2009).</li></ol>

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		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Stainless steel collars</td>
<td>&nbsp;</td>
<td>self-made</td>
<td>&nbsp;</td>
<td>Specially constructed</td>
</tr>
<tr>
<td>Forceps</td>
<td>&nbsp;</td>
<td>Fine Science Tools GmbH</td>
<td>11295-10</td>
<td>&nbsp;</td>
<tr>
<td>Aluminum foil</td>
<td>&nbsp;</td>
<td>Any</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Blade or scalpel</td>
<td>&nbsp;</td>
<td>Any</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Wheaton macro staining jar</td>
<td>&nbsp;</td>
<td>Wheaton Science Products </td>
<td>900200</td>
<td>&nbsp;</td>
<tr>
<td>Microtome</td>
<td>&nbsp;</td>
<td>Carl Zeiss</td>
<td>&nbsp;</td>
<td>Model: Hyrax M25</td>
</tr>
<tr>
<td>Cryo-microtome</td>
<td>&nbsp;</td>
<td>Leica </td>
<td>&nbsp;</td>
<td>Model CM3050S</td>
</tr>
<tr>
<td>60-65&deg;C Incubator</td>
<td>&nbsp;</td>
<td>Any</td>
<td>&nbsp;</td>
<td>Large enough to hold at least 4 staining jars</td>
</tr>
<tr>
<td>Freezing cooler with metal block</td>
<td>&nbsp;</td>
<td>Any</td>
<td>&nbsp;</td>
<td>Store at -80&deg;C</td>
</tr>
<tr>
<td>Super-frost slides</td>
<td>&nbsp;</td>
<td>Thermo Fisher Scientific</td>
<td>9161155</td>
<td>&nbsp;</td>
<tr>
<td>Cover slips</td>
<td>&nbsp;</td>
<td>Any </td>
<td>&nbsp;</td>
<td>Recommend 24 X 40 mm</td>
</tr>
<tr>
<td>Chloroform</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>288306</td>
<td>Analytical grade </td>
</tr>
<tr>
<td>Glacial acetic acid</td>
<td>&nbsp;</td>
<td>Merck</td>
<td>100063</td>
<td>Analytical grade</td>
</tr>
<tr>
<td>Ethanol</td>
<td>&nbsp;</td>
<td>Merck</td>
<td>100983</td>
<td>Analytical grade</td>
</tr>
<tr>
<td>Methylbenzoate</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>M29908-500G</td>
<td>Analytical grade</td>
</tr>
<tr>
<td>Paraplast plus</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>76258</td>
<td>Paraffin</td>
</tr>
<tr>
<td>Tissue-Teck O.C.T. compound</td>
<td>&nbsp;</td>
<td>Sakura</td>
<td>4583</td>
<td>&nbsp;</td>
<tr>
<td>16% formaldehyde, methanol free</td>
<td>&nbsp;</td>
<td>Polysciences</td>
<td>18814</td>
<td>&nbsp;</td>
<tr>
<td>Glycerol</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>G5150-1L</td>
<td>&nbsp;</td>		</tbody>
		</table>
		</div>

paraffin-embedded and frozen sections of drosophila adult muscles

La caractérisation moléculaire des dystrophies musculaires et myopathies chez les humains a révélé la complexité de la maladie du muscle et de l&#39;analyse génétique de la spécification musculaire, la formation et de fonctionner dans des systèmes modèles a fourni des informations précieuses sur la physiologie musculaire. Par conséquent, identifier et caractériser les mécanismes moléculaires qui sous-tendent les dommages musculaires est essentiel. La structure de l&#39;adulte de drosophile multi-fibres musculaires ressemblent vertébrés muscles striés 1 et la traçabilité génétique de la drosophile a fait un excellent système pour analyser la morphologie des muscles dystrophiques et de caractériser les processus qui affectent la fonction musculaire chez les adultes du vieillissement des mouches 2. Ici, nous présentons la technique histologique pour la préparation de paraffine et congelés des sections de muscles thoraciques chez la drosophile. Ces préparations permettent de tissus à teindre avec des colorants histologiques classiques et étiquetés avec des colorants protéines détecter, et plus précisément cryocoupes sont idéales pour la détection immunohistochimique des protéines dans les muscles intacts. Cela permet l&#39;analyse de la structure des tissus musculaires, l&#39;identification des défauts morphologiques, et la détection du patron d&#39;expression pour le muscle / neurone-spécifique des protéines dans les muscles pour adultes drosophile. Ces techniques peuvent aussi être légèrement modifiée pour la coupe d&#39;autres parties du corps.

Watch this Scientific Journal Video about Paraffin-Embedded and Frozen Sections of Drosophila Adult Muscles at JoVE.com

Paraffin-Embedded and Frozen Sections of Drosophila Adult Muscles

L&#39;identification des mécanismes sous-jacents des lésions musculaires est cruciale. Ici, nous présentons la technique histologique pour la préparation de paraffine et congelés des sections de muscles thoraciques chez la drosophile. Cela permet l&#39;analyse de la morphologie des muscles et la localisation des protéines et autres composants de la cellule musculaire.

Les articles inclus en paraffine et congelés de Drosophile</emMuscles adultes>

The molecular characterization of muscular dystrophies and myopathies in humans has revealed the complexity of muscle disease and genetic analysis of ...

paraffin-embedded-and-frozen-sections-of-drosophila-adult-muscles

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JoVE Journal

Biology

Paraffin-Embedded and Frozen Sections of Drosophila Adult Muscles

36.4K vues.  Max Planck Institute for Biophysical Chemistry. L'identification des mécanismes sous-jacents des lésions musculaires est cruciale. Ici, nous présentons la technique histologique pour la préparation de paraffine et congelés des sections de muscles thoraciques chez la drosophile. Cela permet l'analyse de la morphologie des muscles et la localisation des protéines et autres composants de la cellule musculaire.

Vidéo: Paraffin-Embedded and Frozen Sections of Drosophila Adult Muscles

Whole Cell Recordings from Brain of Adult Drosophila

In this video, we demonstrate the procedure for isolating whole brains from adult Drosophila in preparation for recording from single neurons. We begin by describing the dissecting solution and capture of the adult females used in our studies. The procedure for removing the whole brain intact, including both optic lobes, is illustrated. Dissection of the overlying trachea is also shown.  The isolated brain is not only small but needs special care in handling at this stage to prevent damage to the neurons, many of which are close to the outer surface of the tissue. We show how a special holder we developed is used to stabilize the brain in the recording chamber. A standard electrophysiology set up is used for recording from single neurons or pairs of neurons. A fluorescent image, viewed through the recording microscope, from a GAL4 line driving GFP expression (GH146) illustrates how projection neurons (PNs) are identified in the live brain. A high power Nomarski image shows a view of a single neuron that is being targeted for whole cell recording. When the brain is successfully removed without damage, the majority of the neurons are spontaneously active, firing action potentials and/or exhibiting spontaneous synaptic input. This in situ preparation, in which whole cell recording of identified neurons in the whole brain can be combined with genetic and pharmacological manipulations, is a useful model for exploring cellular physiology and plasticity in the adult CNS.

This video demonstrates the procedure for isolating whole brains from adult Drosophila in preparation for recording from single neurons using standard whole cell technology. It includes images of GFP labeled cells and neurons viewed during recording.

Enregistrements à partir de cellules entières du cerveau d&#39;adulte drosophile

In this video, we demonstrate the procedure for isolating whole brains from adult Drosophila in preparation for recording from single neurons. We begin by ...

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Biologie

Preparation of Developing and Adult Drosophila Brains and Retinae for Live Imaging

The Drosophila brain and visual system are widely utilized model systems to study neuronal development, function and degeneration. Here we show three preparations of the brain and visual system that cover the range from the developing eye disc-brain complex in the developing pupae to individual eye and brain dissection from adult flies. All protocols are optimized for the live culture of the preparations. However, we also present the conditions for fixed tissue immunohistochemistry where applicable. Finally, we show live imaging conditions for these preparations using conventional and resonant 4D confocal live imaging in a perfusion chamber. Together, these protocols provide a basis for live imaging on different time scales ranging from functional intracellular assays on the scale of minutes to developmental or degenerative processes on the scale of many hours.

Preparation of Developing and Adult Drosophila Brains and Retinae for Live Imaging

This protocol describes three Drosophila preparations: 1) adult brain dissection, 2) adult retina dissection and 3) developing eye disc- brain complexes dissection. Emphasis is laid on special preparation techniques and conditions for live imaging, although all preparations can be used for fixed tissue immunohistochemistry.

Préparation de développement et de l&#39;adulte Drosophile Cerveaux et la rétine d&#39;imagerie en temps réel

The Drosophila brain and visual system are widely utilized model systems to study neuronal development, function and degeneration. Here we show three ...

Dissection of Oenocytes from Adult Drosophila melanogaster

In Drosophila melanogaster, as in other insects, a waxy layer on the outer surface of the cuticle, composed primarily of hydrocarbon compounds, provides protection against desiccation and other environmental challenges. Several of these cuticular hydrocarbon (CHC) compounds also function as semiochemical signals, and as such mediate pheromonal communications between members of the same species, or in some instances between different species, and influence behavior. Specialized cells referred to as oenocytes are regarded as the primary site for CHC synthesis. However, relatively little is known regarding the involvement of the oenocytes in the regulation of the biosynthetic, transport, and deposition pathways contributing to CHC output. Given the significant role that CHCs play in several aspects of insect biology, including chemical communication, desiccation resistance, and immunity, it is important to gain a greater understanding of the molecular and genetic regulation of CHC production within these specialized cells. The adult oenocytes of D. melanogaster are located within the abdominal integument, and are metamerically arrayed in ribbon-like clusters radiating along the inner cuticular surface of each abdominal segment. In this video article we demonstrate a dissection technique used for the preparation of oenocytes from adult D. melanogaster. Specifically, we provide a detailed step-by-step demonstration of (1) how to fillet prepare an adult Drosophila abdomen, (2) how to identify the oenocytes and discern them from other tissues, and (3) how to remove intact oenocyte clusters from the abdominal integument. A brief experimental illustration of how this preparation can be used to examine the expression of genes involved in hydrocarbon synthesis is included. The dissected preparation demonstrated herein will allow for the detailed molecular and genetic analysis of oenocyte function in the adult fruit fly.

Dissection of Oenocytes from Adult Drosophila melanogaster

In insects, the oenocytes produce cuticular hydrocarbon compounds. These compounds protect against desiccation and facilitate chemical communication. Here we demonstrate a dissection technique used to isolate the oenocytes from adult Drosophila melanogaster, and illustrate how this preparation can be utilized to study genes involved in hydrocarbon synthesis.

Dissection de Oenocytes d&#39;adultes Drosophila melanogaster</em

In Drosophila melanogaster, as in other insects, a waxy layer on the outer surface of the cuticle, composed primarily of hydrocarbon compounds, provides ...

DNA Extraction from Paraffin Embedded Material for Genetic and Epigenetic Analyses

Disease development and progression are characterized by frequent genetic and epigenetic aberrations including chromosomal rearrangements, copy number gains and losses and DNA methylation. Advances in high-throughput, genome-wide profiling technologies, such as microarrays, have significantly improved our ability to identify and detect these specific alterations. However as technology continues to improve, a limiting factor remains sample quality and availability. Furthermore, follow-up clinical information and disease outcome are often collected years after the initial specimen collection. Specimens, typically formalin-fixed and paraffin embedded (FFPE), are stored in hospital archives for years to decades. DNA can be efficiently and effectively recovered from paraffin-embedded specimens if the appropriate method of extraction is applied. High quality DNA extracted from properly preserved and stored specimens can support quantitative assays for comparisons of normal and diseased tissues and generation of genetic and epigenetic signatures 1. To extract DNA from paraffin-embedded samples, tissue cores or microdissected tissue are subjected to xylene treatment, which dissolves the paraffin from the tissue, and then rehydrated using a series of ethanol washes. Proteins and harmful enzymes such as nucleases are subsequently digested by proteinase K. The addition of lysis buffer, which contains denaturing agents such as sodium dodecyl sulfate (SDS), facilitates digestion 2. Nucleic acids are purified from the tissue lysate using buffer-saturated phenol and high speed centrifugation which generates a biphasic solution. DNA and RNA remain in the upper aqueous phase, while proteins, lipids and polysaccharides are sequestered in the inter- and organic-phases respectively. Retention of the aqueous phase and repeated phenol extractions generates a clean sample. Following phenol extractions, RNase A is added to eliminate contaminating RNA. Additional phenol extractions following incubation with RNase A are used to remove any remaining enzyme. The addition of sodium acetate and isopropanol precipitates DNA, and high speed centrifugation is used to pellet the DNA and facilitate isopropanol removal. Excess salts carried over from precipitation can interfere with subsequent enzymatic assays, but can be removed from the DNA by washing with 70% ethanol, followed by centrifugation to re-pellet the DNA 3. DNA is re-suspended in distilled water or the buffer of choice, quantified and stored at -20&deg;C. Purified DNA can subsequently be used in downstream applications which include, but are not limited to, PCR, array comparative genomic hybridization 4 (array CGH), methylated DNA Immunoprecipitation (MeDIP) and sequencing, allowing for an integrative analysis of tissue/tumor samples.

This video demonstrates the protocol for DNA extraction from formalin-fixed paraffin-embedded material. This is a multi-day procedure in which tissue sections are deparaffinized with xylene, rehydrated with ethanol and treated with proteinase K to purify and isolate DNA for subsequent gene-specific or genome-wide analysis.

Extraction d&#39;ADN de matériel inclus en paraffine pour les analyses génétiques et épigénétiques

Disease development and progression are characterized by frequent genetic and epigenetic aberrations including chromosomal rearrangements, copy number ...

Preparation of Adult Drosophila Eyes for Thin Sectioning and Microscopic Analysis

Drosophila has long been used as model system to study development, mainly due to the ease with which it is genetically tractable. Over the years, a plethora of mutant strains and technical tricks have been developed to allow sophisticated questions to be asked and answered in a reasonable amount of time. Fundamental insight into the interplay of components of all known major signaling pathways has been obtained in forward and reverse genetic Drosophila studies. The fly eye has proven to be exceptionally well suited for mutational analysis, since, under laboratory conditions, flies can survive without functional eyes. Furthermore, the surface of the insect eye is composed of some 800 individual unit eyes (facets or ommatidia) that form a regular, smooth surface when looked at under a dissecting microscope. Thus, it is easy to see whether a mutation might affect eye development or growth by externally looking for the loss of the smooth surface ('rough eye' phenotype; Fig. 1) or overall eye size, respectively (for examples of screens based on external eye morphology see e.g.1). Subsequent detailed analyses of eye phenotypes require fixation, plastic embedding and thin-sectioning of adult eyes.
The Drosophila eye develops from the so-called eye imaginal disc, a bag of epithelial cells that proliferate and differentiate during larval and pupal stages (for review see e.g. 2). Each ommatidium consists of 20 cells, including eight photoreceptors (PR or R-cells; Fig. 2), four lens-secreting cone cells, pigment cells ('hexagon' around R-cell cluster) and a bristle. The photoreceptors of each ommatidium, most easily identified by their light sensitive organelles, the rhabdomeres, are organized in a trapezoid made up of the six "outer" (R1-6) and two "inner" photoreceptors (R7/8; R8 [Fig. 2] is underneath R7 and thus only seen in sections from deeper areas of the eye). The trapezoid of each facet is precisely aligned with those of its neighbors and the overall anteroposterior and dorsoventral axes of the eye (Fig. 3A). In particular, the ommatidia of the dorsal and ventral (black and red arrows, respectively) halves of the eye are mirror images of each other and correspond to two chiral forms established during planar cell polarity signaling (for review see e.g. 3).
The method to generate semi-thin eye sections (such as those presented in Fig. 3) described here is slightly modified from the one originally described by Tomlinson and Ready4. It allows the morphological analysis of all cells except for the transparent cone cells. In addition, the pigment of R-cells (blue arrowheads in Fig. 2 and 3) can be used as a cell-autonomous marker for the genotype of a R-cell, thus genetic requirements of genes in a subset of R-cells can readily be determined5,6.

Preparation of Adult Drosophila Eyes for Thin Sectioning and Microscopic Analysis

A standard approach to prepare adult Drosophila eyes for semi-thin sectioning and light microscopic analysis is presented here. The protocol can be used for gross morphological analysis of eye defects, or with the indicated adjustments can be used to determine genetic requirements of genes in specific cell types of the eye (e.g. clonal analysis of photoreceptors) or for electron microscopic analysis.

Préparation des adultes Drosophile Yeux pour la coupe mince et analyse microscopique

Drosophila has long been used as model system to study development, mainly due to the ease with which it is genetically tractable. Over the years, a ...

Proteomic Sample Preparation from Formalin Fixed and Paraffin Embedded Tissue

Preserved clinical material is a unique source for proteomic investigation of human disorders. Here we describe an optimized protocol allowing large scale quantitative analysis of formalin fixed and paraffin embedded (FFPE) tissue. The procedure comprises four distinct steps. The first one is the preparation of sections from the FFPE material and microdissection of cells of interest. In the second step the isolated cells are lysed and processed using 'filter aided sample preparation' (FASP) technique. In this step, proteins are depleted from reagents used for the sample lysis and are digested in two-steps using endoproteinase LysC and trypsin. 
After each digestion, the peptides are collected in separate fractions and their content is determined using a highly sensitive fluorescence measurement. Finally, the peptides are fractionated on 'pipette-tip' microcolumns. The LysC-peptides are separated into 4 fractions whereas the tryptic peptides are separated into 2 fractions. In this way prepared samples allow analysis of proteomes from minute amounts of material to a depth of 10,000 proteins. Thus, the described workflow is a powerful technique for studying diseases in a system-wide-fashion as well as for identification of potential biomarkers and drug targets.

Archival formalin fixed and paraffin embedded (FFPE) clinical samples are valuable material for investigation of diseases. Here we demonstrate a sample preparation workflow allowing in-depth proteomic analysis of microdissected FFPE tissue.

Protéomique Préparation de l&#39;échantillon de formol et inclus en paraffine fixe tissus

Preserved clinical material is a unique source for proteomic investigation of human disorders. Here we describe an optimized protocol allowing large scale ...

qPCR Is a Sensitive and Rapid Method for Detection of Cytomegaloviral DNA in Formalin-fixed, Paraffin-embedded Biopsy Tissue

It is crucial to identify cytomegalovirus (CMV) infection in the gastrointestinal (GI) tract of immunosuppressed patients, given their greater risk for developing severe infection. Many laboratory methods for the detection of CMV infection have been developed, including serology, viral culture, and molecular methods. Often, these methods reflect systemic involvement with CMV and do not specifically identify local tissue involvement. Therefore, detection of CMV infection in the GI tract is frequently done by traditional histology of biopsy tissue. Hematoxylin and eosin (H&#38;E) staining in conjunction with immunohistochemistry (IHC) have remained the mainstays of examining these biopsies. H&#38;E and IHC sometimes result in atypical (equivocal) staining patterns, making interpretation difficult. It was shown that quantitative polymerase chain reaction (qPCR) for CMV can successfully be performed on formalin-fixed, paraffin-embedded (FFPE) biopsy tissue for very high sensitivity and specificity. The goal of this protocol is to demonstrate how to perform qPCR testing for the detection of CMV in FFPE biopsy tissue in a clinical laboratory setting. This method is likely to be of great benefit for patients in cases of equivocal staining for CMV in GI biopsies.

This protocol describes qPCR detection of cytomegalovirus in formalin-fixed, paraffin-embedded biopsy tissue, which is rapid, sensitive, specific, and useful for interpreting equivocal hematoxylin and eosin or immunohistochemical staining patterns.

qPCR est une méthode sensible et rapide pour la détection de l&#39;ADN cytomégalovirus dans la formaline fixe, inclus dans la paraffine des tissus de biopsie

It is crucial to identify cytomegalovirus (CMV) infection in the gastrointestinal (GI) tract of immunosuppressed patients, given their greater risk for ...

Indirect Immunofluorescence on Frozen Sections of Mouse Mammary Gland

Indirect immunofluorescence is used to detect and locate proteins of interest in a tissue. The protocol presented here describes a complete and simple method for the immune detection of proteins, the mouse lactating mammary gland being taken as an example. A protocol for the preparation of the tissue samples, especially concerning the dissection of mouse mammary gland, tissue fixation and frozen tissue sectioning, are detailed. A standard protocol to perform indirect immunofluorescence, including an optional antigen retrieval step, is also presented. The observation of the labeled tissue sections as well as image acquisition and post-treatments are also stated. This procedure gives a full overview, from the collection of animal tissue to the cellular localization of a protein. Although this general method can be applied to other tissue samples, it should be adapted to each tissue/primary antibody couple studied.

The indirect immunofluorescence protocol described in this article allows the detection and the localization of proteins in the mouse mammary gland. A complete method is given to prepare mammary gland samples, to perform immunohistochemistry, to image the tissue sections by fluorescence microscopy, and to reconstruct images.

Immunofluorescence indirecte sur des coupes congelées de glande mammaire de souris

Indirect immunofluorescence is used to detect and locate proteins of interest in a tissue. The protocol presented here describes a complete and simple ...

Employing Digital Droplet PCR to Detect BRAF V600E Mutations in Formalin-fixed Paraffin-embedded Reference Standard Cell Lines

ddPCR is a highly sensitive PCR method that utilizes a water-oil emulsion system. Using a droplet generator, an extracted nucleic acid sample is partitioned into ~20,000 nano-sized, water-in-oil droplets, and PCR amplification occurs in individual droplets. The ddPCR approach is in identifying sequence mutations, copy number alterations, and select structural rearrangements involving targeted genes. Here, we demonstrate the use of ddPCR as a powerful technique for precisely quantitating rare BRAF V600E mutations in FFPE reference standard cell lines, which is helpful in identifying individuals with cancer. In conclusion, ddPCR technique offers the potential to precisely profile the specific rare mutations in different genes in various types of FFPE samples.

The goal of this video is to demonstrate how to perform&#160;automated DNA extraction from formalin-fixed paraffin-embedded (FFPE) reference standard cell lines and digital droplet PCR&#160;(ddPCR) analysis to detect rare mutations in a clinical setting. Detecting mutations in FFPE samples demonstrates the clinical utility of ddPCR in FFPE samples.

Employant numérique Droplet PCR pour détecter des mutations BRAF V600E dans de paraffine standard de référence lignées cellulaires fixés au formol

ddPCR is a highly sensitive PCR method that utilizes a water-oil emulsion system. Using a droplet generator, an extracted nucleic acid sample is ...

Preparation of Formalin-fixed Paraffin-embedded Tissue Cores for both RNA and DNA Extraction

Formalin-fixed paraffin embedded tissue (FFPET) represents a valuable, well-annotated substrate for molecular investigations. The utility of FFPET in molecular analysis is complicated both by heterogeneous tissue composition and low yields when extracting nucleic acids. A literature search revealed a paucity of protocols addressing these issues, and none that showed a validated method for simultaneous extraction of RNA and DNA from regions of interest in FFPET. This method addresses both issues. Tissue specificity was achieved by mapping cancer areas of interest on microscope slides and transferring annotations onto FFPET blocks. Tissue cores were harvested from areas of interest using 0.6 mm microarray punches. Nucleic acid extraction was performed using a commercial FFPET extraction system, with modifications to homogenization, deparaffinization, and Proteinase K digestion steps to improve tissue digestion and increase nucleic acid yields. The modified protocol yields sufficient quantity and quality of nucleic acids for use in a number of downstream analyses, including a multi-analyte gene expression platform, as well as reverse transcriptase coupled real time PCR analysis of mRNA expression, and methylation-specific PCR (MSP) analysis of DNA methylation.

This modified extraction protocol improves RNA and DNA yields from more precisely targeted regions of interest in histopathologic tissue blocks.

Préparation de Cores de tissus enrobés de paraffine fixés au formol pour les ARN et d&#39;extraction d&#39;ADN

Formalin-fixed paraffin embedded tissue (FFPET) represents a valuable, well-annotated substrate for molecular investigations. The utility of FFPET in ...