Name: paraffin-embedded and frozen sections of drosophila adult muscles
Uploaded: 2010-12-27T17:30:00
Duration: 7 min 28 s
Description: Watch this Scientific Journal Video about Paraffin-Embedded and Frozen Sections of Drosophila Adult Muscles at JoVE.com

Vi tackar Prof. Eichele för att tillåta oss att använda Cryo-mikrotomen. Arbetet har finansierats av Max-Planck-Gesselschaft.

1. Förberedelser <ol><li> Färskt förbereda Carnoy är fixativ genom att kombinera absolut etanol, kloroform och isättika i proportion 06:03:01 respektive. 3 Detta, liksom alla lösningar för att sänka ned halsband bör förvaras i glasburkar färgning (se reagenser avsnitt för rekommendation). </li><li> Förbered aluminiumfolie fickor rätt storlek för kragar. </li><li> Förbered följande lösningar i färgning burkar: 2 x 40% etanol, 70% etanol, 2 x 100% etanol, metylbensoat (MB), 50/50 v / v MB och paraffin, 2 X paraffin. Placera MB och behållare paraffin i en inkubator inställd på 60-65 ° C. </li><li> Varmt paraffin att hälla i folie fickor 60-65 ° C. </li></ol> 2. Fastställande Flugor i Halsband <ol><li> Fäst kragen 4 under kikare med tejp i en vertikal position där du kan se ingångspunkt för flugan. </li><li> Bedöva flyger med hjälp av koldioxid eller via hypotermi med ett isblock. Var noga med att inte frysa flugor. </li><li> Använd pincett, plocka upp enskilda flugor genom att ta tag sina vingar och placera in i kragen orienterade ordentligt (huvud och bröstkorg på toppen av bladen och buken nedanför bladen). 10-20 flugor bör lätt passa in i kragen. </li></ol> Obs: Om du analyserar flera genotyper, glöm inte att anteckna kragen numret och motsvarande genotyp. 3. Paraffin av Drosophila Thoraxes <ol><li> Flytta kragen till Carnoy lösning och fixa vävnaden vid 4 ° C över natten. </li><li> Efter fixering, torkar provet med ökande koncentrationer av etanol. För 10 minuter varje dränka kragen till 40% (2 gånger), 70% och 100% (2 gånger) etanol vid rumstemperatur. Nästa inkubera krage i MB och MB + paraffin-lösning (1:1) i 30 min i varje och sedan infiltrera kragen i två förändringar av paraffin i 60 min vardera vid 60-65 ° C. Snabbt flytta kragen in i folie fickan och fyll med smält (60-65 ° C) paraffin. Placera den i rumstemperatur och låt paraffin bli hårt (det är bäst att lämna över natten). Notera att kragen kan placeras i folien fickan i olika inriktningar, beroende på inriktningen på de avsnitt du behöver (längsgående eller tvärgående). </li><li> Packa torrt paraffinblock med kragar från folien och försiktigt separera kragen från paraffin blocket. Med hjälp av en vass kniv eller skalpell Skär försiktigt ut den extra-paraffin från hela flugan vävnad. </li><li> Skär paraffin block med 7-10 steg ìm avsnitt på ett rotationsschema mikrotomen och låta skära vävnaden flyta lägenhet i ett 37 ° C vattenbad. Placera delad vävnad polära diabilder och låt torka över natten. Dessa bilder kan användas för färgning med hematoxyline och eosin (Figur 1A-D), toluidinblått, anilin blå eller annan dör för att visualisera vävnader, samt för antikroppar färgning (Figur 1E-E ``). </li></ol> 4. Kryosnitt av Drosophila Thoraxes <ol><li> Som med paraffin, förbereda flugor i en krage och mode en aluminiumfolie ficka. En frysning kylare kommer att behövas för att förbereda prover. Se till att kylaren är runt -60 ° C, använd lite etanol och torris för att för att nå denna temperatur. En timme innan försöket satte flaskan med Cryo-inbäddning medium (Tissue-Tek oktober förening) upp och ner i en 4 ° C kylskåp för att kyla ner det och för att minimera bildandet av luftbubblor. </li><li> Flytta krage med flyger till folien fickan som har nedkylda i flera minuter inne i frysning svalare och snabbt fylla med Cryo-inbäddning förening. Låt provet frysa i 3-10 min. Försiktigt packa upp bildade blocket inne i svalare, försiktigt separera kragen från inbäddning blocket och satte den vid -20 ° C under minst en dag. </li><li> Skär den frusna musklerna på ett Cryo-mikrotom mellan -15 och -18 ° C med ett avsnitt tjocklek på 10-15 ìm. Placera på polariserade diabilder och hålla vid -20 ° C tills den ska göra vidare bearbetning. Vi föreslår fastställande av vävnad i 4% formaldehyd PBS-lösning för 10 minuter i rumstemperatur före antikroppar färgning. </li></ol> 5. Lipider Påvisande i Drosophila Muskler Lipiddropparna kan upptäckas med olja röda O fläck på kryosnitt hjälp av ett protokoll som antogs av Sieber och Thummel 5. <ol><li> Efter fixering, tvätta objektglasen med vatten två gånger i 5 minuter till jämvikt i propylenglykol i 10 min och inkubera i 3 timmar i olja rött O fläck vid rumstemperatur. Tvätta sedan prover 2 ggr i 5 min i propylenglykol och 30 minuter i PBS. Montera i 30% glycerol. </li></ol> 6. Representativa resultat: <img src="/files/ftp_upload/2438/2438fig1.jpg" alt="Figur 1" /> Figure 1. Parrafin-inbäddade profiler Hematoxyline och eosine färgade tvärgående (AB) och longitudinella (CD) avsnitt av indirekta flyg muskler. A och C visar normal strukturerad muskler. Onormal efter storlek och morfologi muskler är representerade på B respektive D. (svarta pilar). Tvärsnitt af Drosophila bröstkorgen färgade med anti-LamC, kärnhöljet markör och DAPI, kärn-bets (EF). Förstorad bild av normal (röd pil) och försämrades (gul pil) muskler (F). G står för del av Drosophila tarmkanalen färgas med LamC och DAPI. <img src="/files/ftp_upload/2438/2438fig2.jpg" alt="Figur 2" /> Figur 2. Frysta snitt A. Tvärgående frysta snitt av Drosophila bröstkorgen målat med olja röd O, lipiddropparna etikett. B. Längsgående frysta snitt av indirekta flygmuskler färgade med anti-Dg, muskel sarcolemma markör och 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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		<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>
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paraffin-embedded and frozen sections of drosophila adult muscles

Den molekylära karakterisering av muskeldystrofi och myopatier på människa har visat komplexitet muskelsjukdom och genetisk analys av muskel specifikation, har bildning och funktion i modellsystem gett värdefulla insikter i muskelfysiologi. Därför identifiera och karakterisera molekylära mekanismer som ligger bakom muskelskada är kritisk. Strukturen för vuxna Drosophila flera fibrer muskler likna ryggradsdjur tvärstrimmiga musklerna 1 och den genetiska spårbarhet Drosophila har gjort det ett bra system för att analysera dystrofa muskler morfologi och beskriva de processer som påverkar muskelfunktion i åldrande vuxna flugor 2. Här presenterar vi de histologiska teknik för att förbereda paraffininbäddade och frysta delar av Drosophila bröstkorg muskler. Dessa förberedelser möjliggöra vävnad färgas med klassiska histologiska fläckar och märkta med protein upptäcka färgämnen, och särskilt kryosnitt är idealiska för immunhistokemisk detektion av proteiner i intakta muskler. Detta gör det möjligt för analys av muskelvävnad struktur, identifiering av morfologiska defekter, och detektion av uttrycket mönstret för muskel / neuron-specifika proteiner i Drosophila vuxna muskler. Dessa tekniker kan också vara något modifierad för sektionering av andra kroppsdelar.

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

Identifiering av mekanismerna bakom muskelskador är avgörande. Här presenterar vi de histologiska teknik för att förbereda paraffininbäddade och frysta delar av Drosophila bröstkorg muskler. Detta möjliggör analys av muskel morfologi och lokalisering av protein och andra muskel-komponenter cell.

Paraffininbäddade och frysta snitt av Drosophila Vuxen Muskler

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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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.

Helcells Inspelningar från hjärnan hos vuxna 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 ...

High-Resolution Video Tracking of Locomotion in Adult Drosophila Melanogaster

Flies provide an important model for studying complex behavior due to the plethora of genetic tools available to researchers in this field. Studying locomotor behavior in Drosophila melanogaster relies on the ability to be able to quantify changes in motion during or in response to a given task. For this reason, a high-resolution video tracking system, such as the one we describe in this paper, is a valuable tool for measuring locomotion in real-time. Our protocol involves the use of an initial air pulse to break the flies momentum, followed by a thirty second filming period in a square chamber. A tracking program is then used to calculate the instantaneous speed of each fly within the chamber in 10 msec increments. Analysis software then compiles this data, and outputs a variety of parameters such as average speed, max speed, time spent in motion, acceleration, etc. This protocol will discuss proper feeding and management of flies for behavioral tasks, handling flies without anesthetization or immobilization, setting up a controlled environment, and running the assay from start to finish.

The study of complex locomotor behavior in Drosophila melanogaster is dependent upon the ability to quantify changes in a given fly's movement. This article demonstrates how to do this using a high-resolution tracking system.

Högupplöst video Spårning av rörelseorgan hos vuxna Drosophila melanogaster

Flies provide an important model for studying complex behavior due to the plethora of genetic tools available to researchers in this field.  Studying ...

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.

Beredning av Utveckla och vuxna Drosophila Brains och retinae för Live Imaging

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.

Dissekering av Oenocytes från Vuxen 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.

DNA-extraktion från paraffininbäddad Material för genetiska och epigenetiska Analyser

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.

Beredning av vuxna Drosophila Ögon för Thin Sektionering och mikroskopisk analys

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.

Proteomic Provberedning från formalinfixerade och paraffininbäddade vävnads

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 är en känslig och snabb metod för detektion av Cytomegaloviral DNA i formalinfixerade, paraffininbäddade Biopsi Tissue

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.

Indirekt immunofluorescens på frysta sektioner av 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 ...

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.