Este trabajo fue apoyado en parte por el Instituto Nacional del Cáncer P30 CA23074, la Sociedad Americana del Cáncer Investigación Institucional subvención 74-001-31, y la Universidad del. de Arizona GI SPORE (NCI / NIH CA9506O).

<ol>
	<li>Schneider, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+lines+derived+from+late+embryonic+stages+of+Drosophila+melanogaster.">Cell lines derived from late embryonic stages of Drosophila melanogaster.</a> J Embryol Exp Morphol. 27, 353-365 (1972).</li><li>Rogers, S. L., Rogers, G. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Culture+of+Drosophila+S2+cells+and+their+use+for+RNAi-mediated+loss-of-function+studies+and+immunofluorescence+microscopy.">Culture of Drosophila S2 cells and their use for RNAi-mediated loss-of-function studies and immunofluorescence microscopy.</a> Nat Protoc. 3, 606-611 (2008).</li><li>Rogers, S. L., Rogers, G. C., Sharp, D. J., Vale, R. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Drosophila+EB1+is+important+for+proper+assembly,+dynamics,+and+positioning+of+the+mitotic+spindle.">Drosophila EB1 is important for proper assembly, dynamics, and positioning of the mitotic spindle.</a> J Cell Biol. 158, 873-884 (2002).</li><li>Goshima, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genes+required+for+mitotic+spindle+assembly+in+Drosophila+S2+cells.">Genes required for mitotic spindle assembly in Drosophila S2 cells.</a> Science. 316, 417-421 (2007).</li></ol>

Para el campo de la biología celular, un sistema ideal sería barato de mantener, fácil de manipular, y es susceptible de una variedad de técnicas. Células S2 de Drosophila satisfacer estos requisitos, por lo que han convertido rápidamente en el sistema de elección para un creciente número de celular biología de los laboratorios. Hemos presentado un breve resumen de los métodos para preparar las células S2 para microscopía. Una virtud notable de las células S2 es el hech...

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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>S2 cells</td>
<td>&nbsp;</td>
<td>ATCC</td>
<td>CRL-1963</td>
<td><a href="http://www.atcc.org/">http://www.atcc.org/</a></td>
</tr>
<tr>
<td>S2 cells</td>
<td>&nbsp;</td>
<td>DGRC</td>
<td>stock number 6</td>
<td><a href="https://dgrc.cgb.indiana.edu/">https://dgrc.cgb.indiana.edu/</a></td>
</tr>
<tr>
<td>S2 cells</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>R690-07</td>
<td>&nbsp;</td>
<tr>
<td>Sf900 II</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>10902-096</td>
<td>serum-free medium</td>
</tr>
<tr>
<td>HyClone SFX-Insect</td>
<td>&nbsp;</td>
<td>Thermo Scientific</td>
<td>SH30278</td>
<td>serum-free medium</td>
</tr>
<tr>
<td>Insect-Xpress</td>
<td>&nbsp;</td>
<td>BioWhittaker</td>
<td>12-730</td>
<td>serum-free medium</td>
</tr>
<tr>
<td>Schneider's S2 medium</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>11720-034</td>
<td>Add 10% (final) heat-inactivated FBS to make complete medium.</td>
</tr>
<tr>
<td>Fetal bovine serum</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>10438026</td>
<td>heat inactivated</td>
</tr>
<tr>
<td>100x antibiotic solution</td>
<td>&nbsp;</td>
<td>MP Biomedicals</td>
<td>91674049</td>
<td>contains penicillin (10000 U/mL), streptomycin (10000 &mu;g/mL), and amphotericin B (25 &mu;g/mL)</td>
</tr>
<tr>
<td>Concanavalin A</td>
<td>&nbsp;</td>
<td>MP Biomedicals</td>
<td>195283</td>
<td>&nbsp;</td>
<tr>
<td>Formaldehyde</td>
<td>&nbsp;</td>
<td>Electron Microscopy Sciences</td>
<td>15714</td>
<td>32% solution</td>
</tr>
<tr>
<td>Methanol</td>
<td>&nbsp;</td>
<td>Mallinckrodt Baker</td>
<td>9049</td>
<td>anhydrous, ACS grade</td>
</tr>
<tr>
<td>Molecular sieves</td>
<td>&nbsp;</td>
<td>Acros Organics</td>
<td>19724</td>
<td>type 3A</td>
</tr>		</tbody>
		</table>
		</div>

preparation of drosophila s2 cells for light microscopy

El sistema experimental ideal sería barato y fácil de mantener, susceptibles de una variedad de técnicas, y sería apoyado por una extensa bibliografía y base de datos de secuencia del genoma. Cultivos de células S2 de Drosophila, el producto de desvincularse 20-24 embriones horas de edad 1, posee todas estas propiedades. En consecuencia, las células S2 son extremadamente bien adaptado para el análisis de los procesos celulares, incluyendo el descubrimiento de los genes que codifican los componentes moleculares del proceso o mecanismo de interés. Las características de las células S2 que son más responsables de su utilidad son la facilidad con que se mantienen, su exquisita sensibilidad a doble cadena (ds) mediada por RNA de interferencia (RNAi), y su docilidad a la microscopía de fluorescencia, ya sea en vivo o fija las células. S2 células pueden ser cultivadas en una variedad de medios, incluyendo un número de bajo costo, disponibles en el mercado, completamente definido, medio libre de suero 2. Además, crecen de manera óptima y rápida a 21-24 ° C y se pueden cultivar en una variedad de recipientes. A diferencia de las células de mamíferos, las células S2 no requieren de un ambiente regulado, sino hacer bien con el aire normal, e incluso se puede mantener en frascos sellados. Como complemento a la facilidad de ARNi en las células S2 es la capacidad de analizar rápidamente fenotipos inducidos experimentalmente por fase o microscopía de fluorescencia de células fijas o en vivo. S2 células crecen en la cultura como una sola monocapa, pero no muestran inhibición por contacto. En cambio, las células tienden a crecer en colonias en cultivos densos. A baja densidad, las culturas S2 crecido en el vidrio o el plástico de cultivo de tejidos tratados son redondos y poco adheridas. Sin embargo, la citología de las células S2 puede ser mejorado mediante la inducción de ellos para aplanar ampliamente cultivando brevemente sobre una superficie recubierta con la lectina, concanavalina A (ConA) 3. S2 células también pueden ser transfectadas establemente con marcadores de fluorescencia con etiquetas a las estructuras de la etiqueta u orgánulos de interés en las células vivas o fijas. Por lo tanto, el escenario habitual para el análisis microscópico de las células es la siguiente: las primeras células, S2 (que puede tener para expresar transgenes marcadores etiquetados) son tratados por RNAi para eliminar una proteína diana (s). Tiempo de tratamiento RNAi puede ser ajustado para permitir que las diferencias en las proteínas a su vez-sobre la cinética y para minimizar el trauma de células / la muerte si la proteína diana es importante para la viabilidad. A continuación, las células tratadas se transfirió a una placa que contiene un cubreobjetos pre-recubiertos con ConA inducir a las células para difundir y se adhieren firmemente al vidrio. Finalmente, las células son expuestas con la elección del investigador de los modos de microscopía. S2 células son particularmente buenos para los estudios que requieren la visualización ampliada de células vivas ya que estas células mantenerse saludable a temperatura ambiente y la atmósfera normal.

Watch this Scientific Journal Video about Preparation of Drosophila S2 cells for Light Microscopy at JoVE.com

Preparation of Drosophila S2 cells for Light Microscopy

Drosophila Schneider (S2), las células son un sistema cada vez más popular para el descubrimiento y el análisis funcional de los genes. Nuestro objetivo es describir algunas de las técnicas microscópicas que hacen que las células S2 como un sistema experimental cada vez más importante.

Preparación de Drosophila Células S2 para microscopía de luz

The ideal experimental system would be cheap and easy to maintain, amenable to a variety of techniques, and would be supported by an extensive literature ...

preparation-of-drosophila-s2-cells-for-light-microscopy

Research

JoVE Journal

Biology

Preparation of Drosophila S2 cells for Light Microscopy

22.4K vistas.  University of Arizona (UOA). Drosophila Schneider (S2), las células son un sistema cada vez más popular para el descubrimiento y el análisis funcional de los genes. Nuestro objetivo es describir algunas de las técnicas microscópicas que hacen que las células S2 como un sistema experimental cada vez más importante.

Video: Preparation of Drosophila S2 cells for Light Microscopy

Preparation of embryos for Electron Microscopy of the Drosophila embryonic heart tube

The morphogenesis of the Drosophila embryonic heart tube has emerged as a valuable model system for studying cell migration, cell-cell adhesion and cell shape changes during embryonic development. One of the challenges faced in studying this structure is that the lumen of the heart tube, as well as the membrane features that are crucial to heart tube formation, are difficult to visualize in whole mount embryos, due to the small size of the heart tube and intra-lumenal space relative to the embryo. The use of transmission electron microscopy allows for higher magnification of these structures and gives the advantage of examining the embryos in cross section, which easily reveals the size and shape of the lumen. In this video, we detail the process for reliable fixation, embedding, and sectioning of late stage Drosophila embryos in order to visualize the heart tube lumen as well as important cellular structures including cell-cell junctions and the basement membrane.

Preparation of embryos for Electron Microscopy of the Drosophila embryonic heart tube

We describe a process for fixation, embedding, sectioning, and imaging of late stage Drosophila embryos for Trasmission Electron Microscopy of the embryonic heart tube. This technique allows for the visualization of the heart tube lumen as well as the basement membrane, which lines the lumen of the heart.

Preparación de embriones para Microscopía Electrónica de la Drosophila Tubo cardíaco embrionario

The morphogenesis of the Drosophila  embryonic heart tube has emerged as a valuable model system for studying cell migration, cell-cell adhesion and cell ...

Investigación

Biología

Examination of Drosophila Larval Tracheal Terminal Cells by Light Microscopy

Cell shape is critical for cell function. However, despite the importance of cell morphology, little is known about how individual cells generate specific shapes. Drosophila tracheal terminal cells have become a powerful genetic model to identify and elucidate the roles of genes required for generating cellular morphologies. Terminal cells are a component of a branched tubular network, the tracheal system that functions to supply oxygen to internal tissues. Terminal cells are an excellent model for investigating questions of cell shape as they possess two distinct cellular architectures. First, terminal cells have an elaborate branched morphology, similar to complex neurons; second, terminal cell branches are formed as thin tubes and contain a membrane-bound intracellular lumen. Quantitative analysis of terminal cell branch number, branch organization and individual branch shape, can be used to provide information about the role of specific genetic mechanisms in the making of a branched cell. Analysis of tube formation in these cells can reveal conserved mechanisms of tubulogenesis common to other tubular networks, such as the vertebrate vasculature. Here we describe techniques that can be used to rapidly fix, image, and analyze both branching patterns and tube formation in terminal cells within Drosophila larvae. These techniques can be used to analyze terminal cells in wild-type and mutant animals, or genetic mosaics. Because of the high efficiency of this protocol, it is also well suited for genetic, RNAi-based, or drug screens in the Drosophila tracheal system.

Examination of Drosophila Larval Tracheal Terminal Cells by Light Microscopy

Here, we present a method for light microscopy analysis of tracheal terminal cells in Drosophila larvae. This method allows for quick examination of branch and lumen morphology in whole animals and would be useful for analysis of individual mutants or screens for mutations affecting terminal cell development.

El examen de<em&gt; Drosophila</em&gt; Larvas células traqueales de terminales por microscopía de luz

Cell shape is critical for cell function. However, despite the importance of cell morphology, little is known about how individual cells generate specific ...

Organelle Transport in Cultured Drosophila Cells: S2 Cell Line and Primary Neurons.

Drosophila S2 cells plated on a coverslip in the presence of any actin-depolymerizing drug form long unbranched processes filled with uniformly polarized microtubules. Organelles move along these processes by microtubule motors. Easy maintenance, high sensitivity to RNAi-mediated protein knock-down and efficient procedure for creating stable cell lines make Drosophila S2 cells an ideal model system to study cargo transport by live imaging. The results obtained with S2 cells can be further applied to a more physiologically relevant system: axonal transport in primary neurons cultured from dissociated Drosophila embryos. Cultured neurons grow long neurites filled with bundled microtubules, very similar to S2 processes. Like in S2 cells, organelles in cultured neurons can be visualized by either organelle-specific fluorescent dyes or by using fluorescent organelle markers encoded by DNA injected into early embryos or expressed in transgenic flies. Therefore, organelle transport can be easily recorded in neurons cultured on glass coverslips using living imaging. Here we describe procedures for culturing and visualizing cargo transport in Drosophila S2 cells and primary neurons. We believe that these protocols make both systems accessible for labs studying cargo transport.

Organelle Transport in Cultured Drosophila Cells: S2 Cell Line and Primary Neurons.

Drosophila S2 cells and cultured neurons are great systems for imaging of motor-driven organelle transport in vivo. Here we describe detailed protocols for culturing both cell types, their imaging and analysis of transport.

Orgánulos Transporte en Cultivadas<em&gt; Drosophila</em&gt; Celdas: S2 Línea Celular y neuronas primarias.

Drosophila S2 cells plated on a coverslip in the presence of any actin-depolymerizing drug form long unbranched processes filled with uniformly polarized ...

In vivo Clonal Tracking of Hematopoietic Stem and Progenitor Cells Marked by Five Fluorescent Proteins using Confocal and Multiphoton Microscopy

We developed and validated a fluorescent marking methodology for clonal tracking of hematopoietic stem and progenitor cells (HSPCs) with high spatial and temporal resolution to study in vivo hematopoiesis using the murine bone marrow transplant experimental model. Genetic combinatorial marking using lentiviral vectors encoding fluorescent proteins (FPs) enabled cell fate mapping through advanced microscopy imaging. Vectors encoding five different FPs: Cerulean, EGFP, Venus, tdTomato, and mCherry were used to concurrently transduce HSPCs, creating a diverse palette of color marked cells. Imaging using confocal/two-photon hybrid microscopy enables simultaneous high resolution assessment of uniquely marked cells and their progeny in conjunction with structural components of the tissues. Volumetric analyses over large areas reveal that spectrally coded HSPC-derived cells can be detected non-invasively in various intact tissues, including the bone marrow (BM), for extensive periods of time following transplantation. Live studies combining video-rate multiphoton and confocal time-lapse imaging in 4D demonstrate the possibility of dynamic cellular and clonal tracking in a quantitative manner.

In vivo Clonal Tracking of Hematopoietic Stem and Progenitor Cells Marked by Five Fluorescent Proteins using Confocal and Multiphoton Microscopy

Combinatorial 5 fluorescent proteins marking of hematopoietic stem and progenitor cells allows in vivo clonal tracking via confocal and two-photon microscopy, providing insights into bone marrow hematopoietic architecture during regeneration. This method allows non-invasive fate mapping of spectrally-coded HSPCs-derived cells in intact tissues for extensive periods of time following transplantation.

En Tracking Clonal vivo de madre hematopoyéticas y células progenitoras Marcado por cinco proteínas fluorescentes utilizando confocal y Microscopía Multifotónica

We developed and validated a fluorescent marking methodology for clonal tracking of hematopoietic stem and progenitor cells (HSPCs) with high spatial and ...

In Vivo 4-Dimensional Tracking of Hematopoietic Stem and Progenitor Cells in Adult Mouse Calvarial Bone Marrow

Through a delicate balance between quiescence and proliferation, self renewal and production of differentiated progeny, hematopoietic stem cells (HSCs) maintain the turnover of all mature blood cell lineages. The coordination of the complex signals leading to specific HSC fates relies upon the interaction between HSCs and the intricate bone marrow microenvironment, which is still poorly understood[1-2].
We describe how by combining a newly developed specimen holder for stable animal positioning with multi-step confocal and two-photon in vivo imaging techniques, it is possible to obtain high-resolution 3D stacks containing HSPCs and their surrounding niches and to monitor them over time through multi-point time-lapse imaging. High definition imaging allows detecting ex vivo labeled hematopoietic stem and progenitor cells (HSPCs) residing within the bone marrow. Moreover, multi-point time-lapse 3D imaging, obtained with faster acquisition settings, provides accurate information about HSPC movement and the reciprocal interactions between HSPCs and stroma cells.
Tracking of HSPCs in relation to GFP positive osteoblastic cells is shown as an exemplary application of this method. This technique can be utilized to track any appropriately labeled hematopoietic or stromal cell of interest within the mouse calvarium bone marrow space.

In Vivo 4-Dimensional Tracking of Hematopoietic Stem and Progenitor Cells in Adult Mouse Calvarial Bone Marrow

The nature of the interactions between hematopoietic stem and progenitor cells (HSPCs) and bone marrow niches is poorly understood. Custom hardware modifications and a multi-step acquisition protocol allow the use of two-photon and confocal microscopy to image ex vivo labeled HSPCs homed within bone marrow areas, tracking interactions and movement.

En Vivo Tracking 4-Dimensional de madre hematopoyéticas y células progenitoras en ratones adultos de calota de Médula Ósea

Through a delicate balance between quiescence and proliferation, self renewal and production of differentiated progeny, hematopoietic stem cells (HSCs) ...

Generating a &#34;Humanized&#34; Drosophila S2 Cell Line Sensitive to Pharmacological Inhibition of Kinesin-5

Kinetochores are large protein-based structures that assemble on centromeres during cell division and link chromosomes to spindle microtubules. Proper distribution of the genetic material requires that sister kinetochores on every chromosome become bioriented by attaching to microtubules from opposite spindle poles before progressing into anaphase. However, erroneous, non-bioriented attachment states are common and cellular pathways exist to both detect and correct such attachments during cell division. The process by which improper kinetochore-microtubule interactions are destabilized is referred to as error correction. To study error correction in living cells, incorrect attachments are purposely generated via chemical inhibition of kinesin-5 motor, which leads to monopolar spindle assembly, and the transition from mal-orientation to biorientation is observed following drug washout. The large number of chromosomes in many model tissue culture cell types poses a challenge in observing individual error correction events. Drosophila S2 cells are better subjects for such studies as they possess as few as 4 pairs of chromosomes. However, small molecule kinesin-5 inhibitors are ineffective against Drosophila kinesin-5 (Klp61F). Here we describe how to build a Drosophila cell line that effectively replaces Klp61F with human kinesin-5, which renders the cells sensitive to pharmacological inhibition of the motor and suitable for use in the cell-based error correction assay.

Generating a &quot;Humanized&quot; Drosophila S2 Cell Line Sensitive to Pharmacological Inhibition of Kinesin-5

This protocol describes how to generate a Drosophila S2 cell line that is sensitive to small molecule inhibitors of kinesin-5. The use of these cells in a cell-based error correction assay is also outlined.

Generación de un &quot;humanizado&quot;<em&gt; Drosophila</em&gt; S2 Línea Celular Sensible a farmacológico Inhibición de la Kinesin-5

Kinetochores are large protein-based structures that assemble on centromeres during cell division and link chromosomes to spindle microtubules. Proper ...

Drosophila Preparation and Longitudinal Imaging of Heart Function In Vivo Using Optical Coherence Microscopy (OCM)

Longitudinal study of the heartbeat in small animals contributes to understanding structural and functional changes during heart development. Optical coherence microscopy (OCM) has been demonstrated to be capable of imaging small animal hearts with high spatial resolution and ultrahigh imaging speed. The high image contrast and noninvasive properties make OCM ideal for performing longitudinal studies without requiring tissue dissections or staining. Drosophila has been widely used as a model organism in cardiac developmental studies due to its high number of orthologous human disease genes, its similarity of molecular mechanisms and genetic pathways with vertebrates, its short life cycle, and its low culture cost. Here, the experimental protocols are described for the preparation of Drosophila and optical imaging of the heartbeat with a custom OCM system throughout the life cycle of the specimen. By following the steps provided in this report, transverse M-mode and 3D OCM images can be acquired to conduct longitudinal studies of the Drosophila cardiac morphology and function. The en face and axial sectional OCM images and the heart rate (HR) and cardiac activity period (CAP) histograms, were also shown to analyze the heart structural changes and to quantify the heart dynamics during Drosophila metamorphosis, combined with the videos constructed with M-mode images to trace cardiac activity intuitively. Due to the genetic similarity between Drosophila and vertebrates, longitudinal study of heart morphology and dynamics in fruit flies could help reveal the origins of human heart diseases. The protocol here would provide an effective method to perform a wide range of studies to understand the mechanisms of cardiac diseases in humans.

Drosophila Preparation and Longitudinal Imaging of Heart Function In Vivo Using Optical Coherence Microscopy OCM

Here, the experimental protocols are described for preparing Drosophila at different developmental stages and performing longitudinal optical imaging of Drosophila heartbeats using a custom optical coherence microscopy (OCM) system. The cardiac morphological and dynamical changes can be quantitatively characterized by analyzing the heart structural and functional parameters from OCM images.

Drosophila Preparación e Imagen longitudinal de la función cardiaca in vivo utilizando microscopía de coherencia óptica (OCM)

Longitudinal study of the heartbeat in small animals contributes to understanding structural and functional changes during heart development. Optical ...

Biological Sample Preparation by High-pressure Freezing, Microwave-assisted Contrast Enhancement, and Minimal Resin Embedding for Volume Imaging

The described sample preparation technique is designed to combine the best quality of ultrastructural preservation with the most suitable contrast for the imaging modality in a focused ion beam scanning electron microscope (FIB-SEM), which is used to obtain stacks of sequential images for 3D reconstruction and modelling. High-pressure freezing (HPF) allows close to native structural preservation, but the subsequent freeze substitution often does not provide sufficient contrast, especially for a bigger specimen, which is needed for high-quality imaging in the SEM required for 3D reconstruction. Therefore, in this protocol, after the freeze substitution, additional contrasting steps are carried out at room temperature. Although these steps are performed in a microwave, it is also possible to follow traditional bench processing, which requires longer incubation times.The subsequent embedding in minimal amounts of resin allows for faster and more precise targeting and preparation inside the FIB-SEM. This protocol is especially useful for samples that require preparation by high-pressure freezing for a reliable ultrastructural preservation but do not gain enough contrast during the freeze substitution for volume imaging using FIB-SEM. In combination with the minimal resin embedding, this protocol provides an efficient workflow for the acquisition of high-quality volume data.

Here we present a protocol for combining two sample processing techniques, high-pressure freezing and microwave-assisted sample processing, followed by minimal resin embedding for acquiring data with a focused ion beam scanning electron microscope (FIB-SEM). This is demonstrated using a mouse tibial nerve sample and Caenorhabditis elegans.

Preparación de muestras biológicas por congelación de alta presión, realce del contraste asistida por microondas y mínima inclusión de proyección de imagen de volumen

The described sample preparation technique is designed to combine the best quality of ultrastructural preservation with the most suitable contrast for the ...

Light Spot-Based Assay for Analysis of Drosophila Larval Phototaxis

The larvae of Drosophila melanogaster show obvious light-avoiding behavior during the foraging stage. Drosophila larval phototaxis can be used as a model to study animal avoidance behavior. This protocol introduces a light-spot assay to investigate larval phototactic behavior. The experimental set-up includes two main parts: a visual stimulation system that generates the light spot, and an infrared light-based imaging system that records the process of larval light avoidance. This assay allows tracking of the behavior of larva before entering, during encountering, and after leaving the light spot. Details of larval movement including deceleration, pause, head casting, and turning can be captured and analyzed using this method.

Light Spot-Based Assay for Analysis of Drosophila Larval Phototaxis

This protocol introduces a light-spot assay to investigate Drosophila larval phototactic behavior. In this assay, a light spot is generated as light stimulation, and the process of larval light avoidance is recorded by an infrared light-based imaging system.

Ensayo basado en puntos claros para el análisis de la fototaxis larval de Drosophila

The larvae of Drosophila melanogaster show obvious light-avoiding behavior during the foraging stage. Drosophila larval phototaxis can be used as a model ...

Cryo-Electron Microscopic Grid Preparation for Time-Resolved Studies using a Novel Robotic System, Spotiton

The capture of short-lived molecular states triggered by the early encounter of two or more interacting particles continues to be an experimental challenge of great interest to the field of cryo-electron microscopy (cryo-EM). A few methodological strategies have been developed that support these &#34;time-resolved&#34; studies, one of which, Spotiton-a novel robotic system-combines the dispensing of picoliter-sized sample droplets with precise temporal and spatial control. The time-resolved Spotiton workflow offers a uniquely efficient approach to interrogate early structural rearrangements from minimal sample volume. Fired from independently controlled piezoelectric dispensers, two samples land and rapidly mix on a nanowire EM grid as it plunges toward the cryogen. Potentially hundreds of grids can be prepared in rapid succession from only a few microliters of a sample. Here, a detailed step-by-step protocol of the operation of the Spotiton system is presented with a focus on troubleshooting specific problems that arise during grid preparation.

The protocol presented here describes the use of Spotiton, a novel robotic system, to deliver two samples of interest onto a self-wicking, nanowire grid that mix for a minimum of 90 ms prior to vitrification in liquid cryogen.