Una amplia variedad de luciferasa que expresan las líneas celulares de cáncer puede ser utilizado para la investigación preclínica en modelos de ratón. Estas células se proporcionan como una cultura congelada libre de patógenos, que rápidamente crecerá en los medios de comunicación estándar, sin necesidad de marcadores de selección. Para nuestro experimento, vamos a utilizar el 4T1-luc2 murino línea de células tumorales mamarias, que expresa el gen de la luciferasa, que sirve como un indicador óptico de la expresión génica o tumorgenesis in vivo. Vamos a usar la expresión de luciferasa para observar el crecimiento del tumor primario, de forma no invasiva, pero también se puede utilizar para localizar y controlar las lesiones metastásicas. La actividad luciferasa debe ser verificada antes de la inyección, y con el fin de hacer esto, un frasco de 90% confluentes se cosechan por tripsinización y contaron. 50.000 células se entrega en un solo pozo de una placa de microtitulación y diluciones seriadas se llevan a cabo. Luciferina se añade a los pozos de 150ug por ml y se incubó durante 2 minutos. La microplaca se pueden leer en IVIS o un lector de placas luminiscentes para determinar los niveles de expresión. Esta línea celular expresa hasta 6500 fotones por células por segundo, pero cualquier nivel de expresión por encima de 500 fotones por segundo por cada célula se pueden visualizar con éxito en vivo. Ahora que tenemos las células de la actividad óptima, podemos pasar a la etapa de inyección subcutánea. Con el fin de facilitar la detección óptima del tumor, estamos utilizando una cepa atímicos inmunodeficientes ratón desnudo. Antes de la inyección, los animales son anestesiados para llevar a cabo para la anestesia profunda. A continuación vamos a inyectar hasta 250.000 células en 100 ul de PBS se inyectan por vía subcutánea en el flanco. La carga de las células en una jeringa de 1 ml y ponga una aguja de calibre 26. Levante la piel suavemente con unas pinzas para hacer una &quot;tienda&quot; e inyectar las células en la base. Las nuevas células inyectadas se pueden visualizar de inmediato. En cada sesión de imágenes de un total de 150 mg de luciferina por kg de peso luego se administra a través de dos inyecciones en la cavidad peritoneal. En este estudio, los animales son imágenes 10 minutos después de la inyección luciferina para asegurar el flujo de fotones coherentes. Le mostraremos esto en el próximo paso. Cinética de la luciferina puede variar de un día para otro. En este modelo en particular, la medición de 10 minutos después de la inyección luciferina dio un resultado dentro de un rango de 15% de la variabilidad. Para nuestro experimento vamos a utilizar el espectro IVIS en vivo sistema de imágenes utiliza un back-adelgazado dispositivo de carga acoplada refrigerados a -90 ° C para conseguir la máxima sensibilidad. Para apoyar la cuantificación absoluta, el sistema mide la carga oscura durante el tiempo de inactividad y ejecuta una auto-calibración durante la inicialización. Para empezar la imagen, inicializar el sistema IVIS (un clic) y establecer los parámetros de imagen para el experimento. Seleccione el campo de visión para el número de animales que se explora. Hasta 5 animales se pueden mantener en el instrumento a través del colector de anestésico integral. El escenario está en una constante de 37 ° C para mantener la temperatura corporal en los animales. Un puerto de ECG se proporciona para controlar la salud de los animales durante los procedimientos estresantes. Vivir en el software de imagen, tiempo de exposición, diafragmas y pixel binning se puede optimizar en función del nivel de expresión de la línea celular. Estos ajustes se pueden cambiar en cualquier momento durante un experimento sin afectar el resultado cuantitativo. IVIS adquiere una imagen fotográfica de los animales con luz blanca y una señal cuantitativa bioluminiscentes o fluorescentes, que se superpone en la imagen. La señal bioluminiscente se expresa en forma de fotones por segundo y se muestra como un mapa de intensidad. La visualización de la imagen se ajusta para proporcionar un contraste óptimo y la resolución de la imagen sin afectar a la cuantificación. Luminiscencia de las células se puede medir en el lugar de inyección con una región de la herramienta de interés. Los datos de medición se muestran en la tabla, junto con todos los parámetros experimentales relacionados con la captura de imágenes que se pueden guardar o exportar para su análisis Varias imágenes pueden ser adquiridas y comparados en los estudios longitudinales que cubren segundos o meses, dependiendo de la naturaleza del experimento. Vamos a medir el flujo de fotones del tumor en el momento cero y el monitor durante 4 semanas con imágenes a intervalos de dos semanas. Flujo de fotones del tumor es proporcional al número de células vivas que expresan luciferasa para la bioluminiscencia se correlaciona directamente con el tamaño del tumor. A los 5 días posteriores a la implantación del tumor no es aún palpable, pero las células pueden ser cuantificados a través de la bioluminiscencia y el tumor se ve que es de crecimiento activo. En esta etapa la señal de bioluminiscencia es mucho stronger. El tiempo de exposición, f-stop y pixel binning se puede ajustar para que la imagen es clara y la cámara no se sature. IVIS compensa automáticamente los cambios en la recolección de la luz así que estas medidas se puede comparar con los obtenidos antes y después del experimento. A los 7 días después del implante tumores son palpables, por primera vez y bioluminiscencia medida ya ha generado 7 días de datos. A los 28 días posteriores a la implantación, los tumores se están convirtiendo en necrosis y las células comienzan a morir. Estima que el tamaño del tumor mediante un calibre de medición no cambia apreciablemente, pero la luminiscencia del tumor se reducirá lo que indica la muerte celular. Mediciones de la pinza y la medición de bioluminiscencia se puede continuar hasta un punto final que se alcance humano. Necrosis del tumor debido a los regímenes de la hipoxia o el tratamiento será indicado por la bioluminiscencia reducido, incluso si no reducen la masa tumoral.

Me gustaría asegurar que todos los experimentos realizados para producir el artículo del Journal of experimentos visualizados se realizaron en cumplimiento del Protocolo de animales 060 aprobado por el Comité Institucional y el empleo Comisión (IACUC) en Caliper Life Sciences, Alameda CA Jae Kim, Ph . D., Presidente IACUC, Caliper Life Sciences.

in vivo bioluminescent imaging of mammary tumors using ivis spectrum

Células 4T1 de tumor mamario de ratón puede ser implantado subcutáneamente en ratones nu / nu para formar tumores palpables en 15 a 20 días. Este sistema modelo de xenoinjerto tumoral es útil para la pre-clínica en la evaluación in vivo de compuestos antitumorales putativo. La línea celular 4T1 se ha diseñado para expresar constitutivamente el gen de la luciferasa de luciérnaga (luc2). Cuando ratones portadores de tumores 4T1-luc2 son inyectados con luciferina los tumores emiten una señal de luz visible que pueden ser monitoreados utilizando un sistema sensible de imágenes ópticas, como el espectro de IVIS. El flujo de fotones del tumor es proporcional al número de células que emiten luz y la señal puede ser medida para controlar el crecimiento tumoral y el desarrollo. IVIS está calibrada para permitir la cuantificación absoluta de la señal bioluminiscente y los estudios longitudinales se pueden realizar durante muchos meses y en varios órdenes de magnitud de la señal, sin comprometer el resultado cuantitativo. El crecimiento del tumor se puede controlar durante varios días antes de la bioluminiscencia por el tamaño del tumor se hace palpable y mensurable por los tradicionales medios físicos. Este monitoreo rápido puede dar una idea de los primeros eventos en el desarrollo de tumores o dar lugar a procedimientos más cortos experimentales. Muerte de las células del tumor y necrosis debido al tratamiento de la hipoxia o fármaco está indicado temprano por la reducción de la señal bioluminiscente. Esta muerte celular no puede ir acompañado de una reducción en el tamaño del tumor, medido por medios físicos. La capacidad de ver los primeros eventos en necrosis tumoral tiene un impacto significativo en la selección y desarrollo de agentes terapéuticos. Imagen cuantitativa del crecimiento tumoral con IVIS ofrece la cuantificación precisa y acelera el proceso experimental para generar resultados.

Watch this Scientific Journal Video about In vivo Bioluminescent Imaging of Mammary Tumors Using IVIS Spectrum at JoVE.com

In vivo Bioluminescent Imaging of Mammary Tumors Using IVIS Spectrum

Mamaria células tumorales que expresan luciferasa se implanta de forma subcutánea en ratones y se visualizan con imágenes ópticas para controlar el crecimiento tumoral y el desarrollo de forma no invasiva en un estudio longitudinal.

En vivo bioluminiscente de imágenes de tumores de mama mediante el espectro de IVIS

4T1 mouse mammary tumor cells can be implanted sub-cutaneously in nu/nu mice to form palpable tumors in 15 to 20 days. This xenograft tumor model system ...

in-vivo-bioluminescent-imaging-of-mammary-tumors-using-ivis-spectrum

Research

JoVE Journal

Biology

In vivo Bioluminescent Imaging of Mammary Tumors Using IVIS Spectrum

46.8K vistas.  Caliper Life Sciences.  中文 

Video: In vivo Bioluminescent Imaging of Mammary Tumors Using IVIS Spectrum

Dendra2 Photoswitching through the Mammary Imaging Window

In the last decade, intravital microscopy of breast tumors in mice and rats at single-cell resolution1-4 has resulted in important insights into mechanisms of metastatic behavior such as migration, invasion and intravasation of tumor cells5, 6, angiogenesis3 and immune cells response7-9. We have recently reported a technique to image orthotopic mammary carcinomas over multiple intravital imaging sessions in living mice10. For this, we have developed a Mammary Imaging Window (MIW) and optimized imaging parameters for Dendra211 photoswitching and imaging in vivo. Here, we describe the protocol for the manufacturing of MIW, insertion of the MIW on top of a tumor and imaging of the Dendra2- labeled tumor cells using a custom built imaging box. This protocol can be used to image the metastatic behavior of tumor cells in distinct microenvironments in tumors and allows for long term imaging of blood vessels, tumor cells and host cells.

Intravital photoswitching and tracking of Dendra2-labeled tumor cells through the Mammary Imaging Window is a technique which allows us to image the metastatic behavior of tumor cells in chosen tumor microenvironments over a timescale of days.

Dendra2 Photoswitching a través de la ventana de imágenes mamarias

In the last decade, intravital microscopy of breast tumors in mice and rats at single-cell resolution1-4  has resulted in important insights into ...

Investigación

Biología

In vivo Imaging of Deep Cortical Layers using a Microprism

We present a protocol for in vivo imaging of cortical tissue using a deep-brain imaging probe in the shape of a microprism.  Microprisms are 1-mm in size and have a reflective coating on the hypotenuse to allow internal reflection of excitation and emission light.  The microprism probe simultaneously images multiple cortical layers with a perspective typically seen only in slice preparations.  Images are collected with a large field-of-view (~900 &mu;m).  In addition, we provide details on the non-survival surgical procedure and microscope setup.  Representative results include images of layer V pyramidal neurons from Thy-1 YFP-H mice showing their apical dendrites extending through the superficial cortical layer and extending into tufts.  Resolution was sufficient to image dendritic spines near the soma of layer V neurons.  A tail-vein injection of fluorescent dye reveals the intricate network of blood vessels in the cortex.  Line-scanning of red blood cells (RBCs) flowing through the capillaries reveals RBC velocity and flux rates can be obtained. This novel microprism probe is an elegant, yet powerful new method of visualizing deep cellular structures and cortical function in vivo.

In vivo Imaging of Deep Cortical Layers using a Microprism

Right-angle microprisms inserted into the mouse neocortex allows for deep imaging of multiple cortical layers with a viewpoint typically found in slice. One-millimeter microprisms offer a wide field-of-view (~900 &mu;m) and spatial resolutions sufficient to resolve dendritic spines. We demonstrate layer V neuronal imaging and neocortical vascular imaging using microprisms.

Imágenes in vivo de Deep capas corticales con un microprisma

We present a protocol for in vivo imaging of cortical tissue using a deep-brain imaging probe in the shape of a microprism.  Microprisms are 1-mm in size ...

Mesoscopic Fluorescence Tomography for In-vivo Imaging of Developing Drosophila

Visualizing developing organ formation as well as progession and treatment of disease often heavily relies on the ability to optically interrogate molecular and functional changes in intact living organisms. Most existing optical imaging methods are inadequate for imaging at dimensions that lie between the penetration limits of modern optical microscopy (0.5-1mm) and the diffusion-imposed limits of optical macroscopy (&gt;1cm) [1]. Thus, many important model organisms, e.g. insects, animal embryos or small animal extremities, remain inaccessible for in-vivo optical imaging. 
Although there is increasing interest towards the development of nanometer-resolution optical imaging methods, there have not been many successful efforts in improving the imaging penetration depth. The ability to perform in-vivo imaging beyond microscopy limits is in fact met with the difficulties associated with photon scattering present in tissues. Recent efforts to image entire embryos for example [2,3] require special chemical treatment of the specimen, to clear them from scattering, a procedure that makes them suitable only for post-mortem imaging. These methods however evidence the need for imaging larger specimens than the ones usually allowed by two-photon or confocal microscopy, especially in developmental biology and in drug discovery.
We have developed a new optical imaging technique named Mesoscopic Fluorescence Tomography [4], which appropriate for non-invasive in-vivo imaging at dimensions of 1mm-5mm. The method exchanges resolution for penetration depth, but offers unprecedented tomographic imaging performance and it has been developed to add time as a new dimension in developmental biology observations (and possibly other areas of biological research) by imparting the ability to image the evolution of fluorescence-tagged responses over time. As such it can accelerate studies of morphological or functional dependencies on gene mutations or external stimuli, and can importantly, capture the complete picture of development or tissue function by allowing longitudinal time-lapse visualization of the same, developing organism.
The technique utilizes a modified laboratory microscope and multi-projection illumination to collect data at 360-degree projections. It applies the Fermi simplification to Fokker-Plank solution of the photon transport equation, combined with geometrical optics principles in order to build a realistic inversion scheme suitable for mesoscopic range. This allows in-vivo whole-body visualization of non-transparent three-dimensional structures in samples up to several millimeters in size.
We have demonstrated the in-vivo performance of the technique by imaging three-dimensional structures of developing Drosophila tissues in-vivo and by following the morphogenesis of the wings in the opaque Drosophila pupae in real time over six consecutive hours.

Mesoscopic Fluorescence Tomography for In-vivo Imaging of Developing Drosophila

Mesoscopic fluorescence tomography operates beyond the penetration limits of tissue-sectioning fluorescence microscopy. The technique is based on multi-projection illumination and a photon transport description. We demonstrate in-vivo whole-body 3D visualization of the morphogenesis of GFP-expressing wing imaginal discs in Drosophila melanogaster.

Mesoscópica fluorescencia Tomografía por En vivo Imágenes de desarrollo Drosophila</em

Visualizing  developing organ formation as well as progession and treatment of disease often  heavily relies on the ability to optically interrogate ...

Imaging Protein-protein Interactions in vivo

Protein-protein interactions are a hallmark of all essential cellular processes. However, many of these interactions are transient, or energetically weak, preventing their identification and analysis through traditional biochemical methods such as co-immunoprecipitation. In this regard, the genetically encodable fluorescent proteins (GFP, RFP, etc.) and their associated overlapping fluorescence spectrum have revolutionized our ability to monitor weak interactions in vivo using F&ouml;rster resonance energy transfer (FRET)1-3. Here, we detail our use of a FRET-based proximity assay for monitoring receptor-receptor interactions on the endothelial cell surface.

Imaging Protein-protein Interactions in vivo

This protocol describes how to image protein-protein interactions using a FRET-based proximity assay.

Imágenes de interacciones proteína-proteína In vivo</em

Protein-protein interactions are a hallmark of all essential cellular processes. However, many of these interactions are transient, or energetically weak, ...

Single-molecule Imaging of Gene Regulation In vivo Using Cotranslational Activation by Cleavage (CoTrAC)

We describe a fluorescence microscopy method, Co-Translational Activation by Cleavage (CoTrAC) to image the production of protein molecules in live cells with single-molecule precision without perturbing the protein's functionality. This method makes it possible to count the numbers of protein molecules produced in one cell during sequential, five-minute time windows. It requires a fluorescence microscope with laser excitation power density of ~0.5 to 1 kW/cm2, which is sufficiently sensitive to detect single fluorescent protein molecules in live cells. The fluorescent reporter used in this method consists of three parts: a membrane targeting sequence, a fast-maturing, yellow fluorescent protein and a protease recognition sequence. The reporter is translationally fused to the N-terminus of a protein of interest. Cells are grown on a temperature-controlled microscope stage. Every five minutes, fluorescent molecules within cells are imaged (and later counted by analyzing fluorescence images) and subsequently photobleached so that only newly translated proteins are counted in the next measurement.
Fluorescence images resulting from this method can be analyzed by detecting fluorescent spots in each image, assigning them to individual cells and then assigning cells to cell lineages. The number of proteins produced within a time window in a given cell is calculated by dividing the integrated fluorescence intensity of spots by the average intensity of single fluorescent molecules. We used this method to measure expression levels in the range of 0-45 molecules in single 5 min time windows. This method enabled us to measure noise in the expression of the &lambda; repressor CI, and has many other potential applications in systems biology.

Single-molecule Imaging of Gene Regulation In vivo Using Cotranslational Activation by Cleavage CoTrAC

We describe a fluorescence microscopy method, Co-Translational Activation by Cleavage (CoTrAC), to image the production of protein molecules in live cells with single-molecule precision without perturbing the protein's functionality. This method has been used to follow the stochastic expression dynamics of a transcription factor, the &lambda; repressor CI 1.

Una sola molécula de imágenes del Reglamento Gene<em&gt; En vivo</em&gt; Utilización de la activación cotraduccional por escisión (COTRAC)

We describe a fluorescence microscopy method, Co-Translational Activation by Cleavage (CoTrAC) to image the production of protein molecules in live cells ...

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) ...

gDNA Enrichment by a Transposase-based Technology for NGS Analysis of the Whole Sequence of BRCA1, BRCA2, and 9 Genes Involved in DNA Damage Repair

The widespread use of Next Generation Sequencing has opened up new avenues for cancer research and diagnosis. NGS will bring huge amounts of new data on cancer, and especially cancer genetics. Current knowledge and future discoveries will make it necessary to study a huge number of genes that could be involved in a genetic predisposition to cancer. In this regard, we developed a Nextera design to study 11 complete genes involved in DNA damage repair. This protocol was developed to safely study 11 genes (ATM, BARD1, BRCA1, BRCA2, BRIP1, CHEK2, PALB2, RAD50, RAD51C, RAD80, and TP53) from promoter to 3&#39;-UTR in 24 patients simultaneously. This protocol, based on transposase technology and gDNA enrichment, gives a great advantage in terms of time for the genetic diagnosis thanks to sample multiplexing. This protocol can be safely used with blood gDNA.

gDNA Enrichment by a Transposase-based Technology for NGS Analysis of the Whole Sequence of BRCA1, BRCA2, and 9 Genes Involved in DNA Damage Repair

gDNA enrichment for NGS sequencing is an easy and powerful tool for the study of constitutional mutations. In this article, we present the procedure to analyse simply the complete sequence of 11 genes involved in DNA damage repair.

gDNA Enriquecimiento por una tecnología basada en la transposasa de Análisis NGS de la secuencia entera de<em&gt; BRCA1</em&gt;,<em&gt; BRCA2</em&gt;, y 9 genes involucrados en la reparación del ADN daños

The widespread use of Next Generation Sequencing has opened up new avenues for cancer research and diagnosis. NGS will bring huge amounts of new data on ...

A Screenable In Vivo Assay for Mitochondrial Modulators Using Transgenic Bioluminescent Caenorhabditis elegans

The multicellular model organism Caenorhabditis elegans is a small nematode of approximately 1 mm in size in adulthood that is genetically and experimentally tractable. It is economical and easy to culture and dispense in liquid medium which makes it well suited for medium-throughput screening. We have previously validated the use of transgenic luciferase expressing C. elegans strains to provide rapid in vivo assessment of the nematode&#8217;s ATP levels.1-3 Here we present the required materials and procedure to carry out bioassays with the bioluminescent C. elegans strains PE254 or PE255 (or any of their derivative strains). The protocol allows for in vivo detection of sublethal effects of drugs that may identify mitochondrial toxicity, as well as for in vivo detection of potential beneficial drug effects. Representative results are provided for the chemicals paraquat, rotenone, oxaloacetate and for four firefly luciferase inhibitory compounds. The methodology can be scaled up to provide a platform for screening drug libraries for compounds capable of modulating mitochondrial function. Pre-clinical evaluation of drug toxicity is often carried out on immortalized cancerous human cell lines which derive ATP mostly from glycolysis and are often tolerant of mitochondrial toxicants.4,5 In contrast, C. elegans depends on oxidative phosphorylation to sustain development into adulthood, drawing a parallel with humans and providing a unique opportunity for compound evaluation in the physiological context of a whole live multicellular organism.

A Screenable In Vivo Assay for Mitochondrial Modulators Using Transgenic Bioluminescent Caenorhabditis elegans

A protocol is described for in vivo detection of effects of mitochondrial inhibitors in the model organism Caenorhabditis elegans and for identification of potential enhancing compounds. This protocol can be used to screen drug libraries for compounds modulating mitochondrial function.

Un rastreable<em&gt; En Vivo</em&gt; Ensayo para mitocondrial Moduladores Usando transgénico bioluminiscente<em&gt; Caenorhabditis elegans</em

The multicellular model organism Caenorhabditis elegans is a small nematode of approximately 1 mm in size in adulthood that is genetically and ...

Measuring the Stiffness of Ex Vivo Mouse Aortas Using Atomic Force Microscopy

Arterial stiffening is a significant risk factor and biomarker for cardiovascular disease and a hallmark of aging. Atomic force microscopy (AFM) is a versatile analytical tool for characterizing viscoelastic mechanical properties for a variety of materials ranging from hard (plastic, glass, metal, etc.) surfaces to cells on any substrate. It has been widely used to measure the stiffness of cells, but less frequently used to measure the stiffness of aortas. In this paper, we will describe the procedures for using AFM in contact mode to measure the ex vivo elastic modulus of unloaded mouse arteries. We describe our procedure for isolation of mouse aortas, and then provide detailed information for the AFM analysis. This includes step-by-step instructions for alignment of the laser beam, calibration of the spring constant and deflection sensitivity of the AFM probe, and acquisition of force curves. We also provide a detailed protocol for data analysis of the force curves.

Measuring the Stiffness of Ex Vivo Mouse Aortas Using Atomic Force Microscopy

We present detailed protocols for isolation of aortas from mouse and measurement of their elastic modulus using atomic force microscopy.

La medición de la rigidez de<em&gt; Ex Vivo</em&gt; Ratón aortas Usando microscopía de fuerza atómica

Arterial stiffening is a significant risk factor and biomarker for cardiovascular disease and a hallmark of aging. Atomic force microscopy (AFM) is a ...

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 ...