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1. Mica e Slides Preparação <ol><li> Lugar No. 1 ½ (0,17 mm) em lamelas suporte de coloração. </li><li> Sonicar durante 30 min em 2% de detergente a 60 ° C. </li><li> Lave 20 vezes com água deionizada. </li><li> Retirar as lâminas usando uma pinça e secar com ar comprimido ou nitrogênio. </li><li> Corte folha mica em 10 x 10 mm pedaços quadrados usando uma tesoura ou lâmina de barbear. </li><li> Corte cada pedaço mica em 2-3 folhetos finas utilizando lâmina de barbear. NOTA: Esta etapa exige o uso de lâmina afiada. </li></ol> 2. Assembléia Mica e da Câmara de montagem <ol><li> Limpe lâmina de vidro microscópicas com etanol. </li><li> Glue folheto de mica cortado no passo 1.6 a lâmina de vidro com adesivo óptico. Adesivo de baixa viscosidade é aconselhável para melhor difundir a queda e cole a mica. </li><li> Cure sob a lâmpada UV, 10 min. NOTA: O adesivo é curado por luz UV com uma absorção máxima na gama de 350 a 380nm e a energia recomendado required para cura total é de 4,5 J / cm 2. No entanto, as diferentes fontes de luz pode ser utilizado para este passo (ver materiais fornecidos pelo fornecedor de adesivo). </li><li> Expor uma superfície mica limpo, eliminando as primeiras camadas com fita adesiva. </li><li> Coloque uma pequena gota (~ 20 mM) de adesivo óptico sobre a superfície da mica. NOTA: Nesta etapa, adesivo de alta viscosidade, com baixo nível de autofluorescência é aconselhada. Nossa experiência mostrou que o uso de combinação de baixo (passo 2.2) e adesivos de alta viscosidade aumenta significativamente a eficácia da divisão mica (passo 2.7). </li><li> Delicadamente, coloque lamela limpo de fresco para a gota de cola, evitando bolhas de ar, vamos contentar com 1 min. </li><li> Cure sob a lâmpada UV, 10 min. NOTA: após esta etapa, a sanduíche da lâmina de vidro, mica e lamela pode ser armazenado por um período relativamente longo de tempo (até algumas semanas). Vá para a próxima etapa, pouco antes da preparação real SLB, para certificar-se da superfície da mica é fresco. NOTA: O adesivo é curado por luz UV com uma absorção máxima na gama de 350 a 380nm e a energia necessária para recomendada a cura completa é 4.5J/cm 2. No entanto, as diferentes fontes de luz pode ser utilizado para este passo (ver materiais fornecidos pelo fornecedor de adesivo). </li><li> Usando um estilete, desmontar cuidadosamente a lamela de lâmina de vidro lateral, como mostrado no vídeo. Na maioria dos casos, uma camada fina e plana de mica permanecerá ligado à lamela. Mica ligado a lâmina de vidro podem ser reutilizados (repita a partir do passo 2.4). </li><li> Verificar a qualidade da superfície ao olho nu ou sob um microscópio de dissecação, a certificar-se de que a camada de mica ainda está colada à lamela e não foi completamente removido durante a cisão no passo 2.8. Fazendo um pequeno arranhão com uma pinça ou agulha de dissecação ajudará a distinguir entre o adesivo que tem uma consistência diferente detectável a partir de mica. </li><li> Remova a vedação de borracha a partir de um frasco de tampa de 1,5 ml e cola a tampa de cabeça para baixo para a superfície, usando ópticaadesiva ou unha polonês, e curar com lâmpada UV, ou deixar que o ar seco 10 min, respectivamente. NOTA: Se a amostra é preparada para simultânea óptico (TIRFM ou confocal) com imagens de AFM, um ml frasco cap 1.5 pode ser muito pequeno para montar a cabeça AFM no palco microscópio. Nesse caso, o tampão pode ser substituído por qualquer plástico junta tórica com um diâmetro maior, adequado para a montagem de cabeça de AFM. No caso, quando o experimento requer remoção da tampa, sem danificar a superfície de mica, graxa de silicone pode ser usado em vez de cola ou unha polonês. </li></ol> 3. Formação Apoiado Lipid Bilayer (SLB) <ol><li> Coloque solução de lipossomas preparados na hora na câmara com a superfície. O volume mínimo necessário para a formação de SLB é ~ 30 ul. NOTA: Para obter mais detalhes sobre o lipossoma e formação SLB, referem-se a protocolos publicados, tais como tais como Bolsa et al, 2014 15.. </li><li> Prossiga com formação SLB usando o protocolo desejado. Durante a incubação eimagiologia, a câmara pode ser colocada num bloco de calor ou fase de microscópio aquecida para manter a temperatura necessária para manter os lípidos sendo utilizadas acima da sua temperatura de fusão. </li></ol>

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	<li>Giocondi, M. -. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surface+topography+of+membrane+domains.">Surface topography of membrane domains.</a> Biochimica et Biophysica Acta (BBA) - Biomembranes. 1798, 703-718 (2010).</li><li>Garcia-Saez, A. J., Schwille, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surface+analysis+of+membrane+dynamics.">Surface analysis of membrane dynamics.</a> Biochim Biophys Acta. 1798, 766-776 (2010).</li><li>Plochberger, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cholesterol+slows+down+the+lateral+mobility+of+an+oxidized+phospholipid+in+a+supported+lipid+bilayer.">Cholesterol slows down the lateral mobility of an oxidized phospholipid in a supported lipid bilayer.</a> Langmuir. 26, 17322-17329 (2010).</li><li>El Kirat, K., Morandat, S., Dufr&#234;ne, Y. 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A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microcontact+printing+for+creation+of+patterned+lipid+bilayers+on+tetraethylene+glycol+self-assembled+monolayers.">Microcontact printing for creation of patterned lipid bilayers on tetraethylene glycol self-assembled monolayers.</a> Langmuir. 27, 12052-12057 (2011).</li><li>Satriano, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Plasma+oxidized+polyhydroxymethylsiloxane--a+new+smooth+surface+for+supported+lipid+bilayer+formation.">Plasma oxidized polyhydroxymethylsiloxane--a new smooth surface for supported lipid bilayer formation.</a> Langmuir. 26, 5715-5725 (2010).</li><li>Bag, N., Sankaran, J., Paul, A., Kraut, R. S., Wohland, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Calibration+and+limits+of+camera-based+fluorescence+correlation+spectroscopy:+a+supported+lipid+bilayer+study.">Calibration and limits of camera-based fluorescence correlation spectroscopy: a supported lipid bilayer study.</a> Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry. 13, 2784-2794 (2012).</li><li>Singh, S., Keller, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Atomic+force+microscopy+of+supported+planar+membrane+bilayers.">Atomic force microscopy of supported planar membrane bilayers.</a> Biophysical Journal. 60, 1401-1410 (1991).</li><li>Przybylo, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lipid+Diffusion+in+Giant+Unilamellar+Vesicles+Is+More+than+2+Times+Faster+than+in+Supported+Phospholipid+Bilayers+under+Identical+Conditions.">Lipid Diffusion in Giant Unilamellar Vesicles Is More than 2 Times Faster than in Supported Phospholipid Bilayers under Identical Conditions.</a> Langmuir. 22, 9096-9099 (2006).</li><li>Scomparin, C., Lecuyer, S., Ferreira, M., Charitat, T., Tinland, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diffusion+in+supported+lipid+bilayers:+influence+of+substrate+and+preparation+technique+on+the+internal+dynamics.">Diffusion in supported lipid bilayers: influence of substrate and preparation technique on the internal dynamics.</a> Eur Phys J E Soft Matter. 28, 211-220 (2009).</li><li>Oreopoulos, J., Yip, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Combined+scanning+probe+and+total+internal+reflection+fluorescence+microscopy.">Combined scanning probe and total internal reflection fluorescence microscopy.</a> Methods. 46, 2-10 (2008).</li><li>Shaw, J. E., Slade, A., Yip, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simultaneous+in+situ+total+internal+reflectance+fluorescence/atomic+force+microscopy+studies+of+DPPC/dPOPC+microdomains+in+supported+planar+lipid+bilayers.">Simultaneous in situ total internal reflectance fluorescence/atomic force microscopy studies of DPPC/dPOPC microdomains in supported planar lipid bilayers.</a> J Am Chem Soc. 125, 11838-11839 (2003).</li><li>Skaug, M. J., Faller, R., Longo, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Correlating+anomalous+diffusion+with+lipid+bilayer+membrane+structure+using+single+molecule+tracking+and+atomic+force+microscopy.">Correlating anomalous diffusion with lipid bilayer membrane structure using single molecule tracking and atomic force microscopy.</a> J Chem Phys. 134, (2011).</li><li>Bag, N., Yap, D. H., Wohland, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Temperature+dependence+of+diffusion+in+model+and+live+cell+membranes+characterized+by+imaging+fluorescence+correlation+spectroscopy.">Temperature dependence of diffusion in model and live cell membranes characterized by imaging fluorescence correlation spectroscopy.</a> Biochimica et Biophysica Acta. , (2013).</li><li>Sbalzarini, I. F., Koumoutsakos, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Feature+point+tracking+and+trajectory+analysis+for+video+imaging+in+cell+biology.">Feature point tracking and trajectory analysis for video imaging in cell biology.</a> J Struct Biol. 151, 182-195 (2005).</li><li>Linkert, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Metadata+matters:+access+to+image+data+in+the+real+world.">Metadata matters: access to image data in the real world.</a> J Cell Biol. 189, 777-782 (2010).</li><li>Schutz, G. J., Schindler, H., Schmidt, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single-molecule+microscopy+on+model+membranes+reveals+anomalous+diffusion.">Single-molecule microscopy on model membranes reveals anomalous diffusion.</a> Biophys J. 73, 1073-1080 (1997).</li><li>Matysik, A., Kraut, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=TrackArt:+the+user+friendly+interface+for+single+molecule+tracking+data+analysis+and+simulation+applied+to+complex+diffusion+in+mica+supported+lipid+bilayers.">TrackArt: the user friendly interface for single molecule tracking data analysis and simulation applied to complex diffusion in mica supported lipid bilayers.</a> BMC Research Notes. 7, (2014).</li></ol>

Os autores não têm nada a revelar.

Este protocolo descreve um método para a preparação de superfícies lisas e de mica fina para deposição de bicamada lipídica e de alta resolução de imagem. A técnica requer habilidades manuais mínimos, limitado principalmente para a desmontagem cuidadosa do sanduíche vidro-mica-vidro (passo 2.8), que é fundamental para a obtenção de uma superfície de mica de alta qualidade. A inspecção da mica clivada de fresco é sempre necessário, neste ponto, uma vez que é possível para a mica de separar da subst?...

O objetivo geral do presente protocolo é mostrar um método para preparar superfícies de mica em alta resolução de imagem de mica suportada bicamadas lipídicas (EBSL) utilizando microscopia óptica de fluorescência total de reflexão interna (TIRFM) ou microscopia confocal, que também poderia ser combinada com a força atômica microscopia (AFM). EBSL é um modelo amplamente usado para numerosos estudos de agrupamento lipídico, a separação de fases, a dinâmica de componentes de bicamada ou as suas interacções com peptídeos, proteínas ou outros compostos 1-5. Substratos diferentes podem ser usadas para a formação de SLB (isto é, vidro, mica, dióxido de silício, polímeros), dependendo da natureza do estudo 4,6-8. Estudos de membrana típicas contam com técnicas de imagem com base em microscopia, como TIRFM e AFM. Assim, para a imagiologia TIRFM, uma superfície de vidro é uma escolha típica porque o vidro é transparente. Preparação de vidro é relativamente fácil, e a qualidade dos resultados é primariamentedeterminada pela superfície limpeza completa antes da deposição de vesículas lipídicas. AFM, devido à sua alta resolução axial requer superfícies mica. Mica é um mineral de silicato, com cerca de clivagem basal perfeita. Assim, a mica recém clivada é atomicamente plana, permitindo a observação da membrana diferenças de altura, mesmo em escala sub-nanométrica 9. Estudos de difusão, utilizando métodos como a espectroscopia de correlação de fluorescência (FCS), seguindo molécula única (SMT), e recuperação de fluorescência após a fotodegradação (FRAP) mostrou no entanto, que a dinâmica da membrana lipídica depender muito do tipo de superfície sobre a qual são depositados, em que vidro mica e pode dar resultados muito diferentes 10,11. Estas diferenças incluem não apenas os coeficientes de difusão das sondas de membrana, mas também a detecção de populações distintas de partículas que difundem a taxas diferentes, e, possivelmente, a comutação entre os diferentes estados. Assim,a comparação directa dos resultados obtidos utilizando técnicas de TIRFM e AFM é muitas vezes problemática, a menos que a mesma superfície (neste caso, a mica) é usado. Embora existam alguns estudos onde TIRFM e AFM bicamada de imagem foi realizado na mesma superfície mica 12,13, mica é raramente usado para a microscopia óptica, principalmente por causa de problemas de manuseio. Preparação mica requer corte à mão em folhetos finos, que são então coladas à lamela utilizando adesiva óptica 12. Este método, porém, requer um pouco de prática para alcançar resultados satisfatórios. Além disso, as superfícies obtidas são muitas vezes ondulado e grosso, tornando-os difíceis de usar com baixa distância de trabalho, lentes de alta abertura numérica. Mica superfícies preparadas como descrito no presente protocolo são muito finas (~ 220 mM, incluindo a espessura da lamela de 170 um) e extremamente lisa, evitando &quot;ondulação&quot;, o qual é crítico para uma imagem com alta resolução. Eles podem ser utilizadospara TIRFM ou confocal setups. Além disso, as mesmas amostras podem ser transferidos para a AFM, e ainda visualizados simultaneamente com TIRFM / confocal e AFM. A combinação destas duas técnicas permite correlação direta do comportamento de difusão com a estrutura da membrana de bicamada 14. Como as superfícies de mica são recém-clivada, são limpos e não necessitam de demorado, pouco reprodutível, e procedimentos de limpeza potencialmente perigosas (protocolos de limpeza de vidro geralmente incluem produtos químicos como solução Piranha, ácido sulfúrico, hidróxido de sódio / potássio). Montagem de uma pequena câmara, também descrito no protocolo, reduz o volume de vesículas necessários para a formação de bicamada eficaz para menos de 50 ul. Finalmente, todo o processo de montagem de superfície não é demorado (preparação leva menos do que 30 min), e não requerem um elevado grau de habilidade manual, tal como a clivagem de mica convencional e colagem.

<table border="0" cellpadding="0" cellspacing="0" width="710">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:291px;">Name of Material/ Equipment</td>
			<td style="width:135px;">Company</td>
			<td style="width:119px;">Catalog Number</td>
			<td style="width:167px;">Comments/Description</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:291px;">Bath Sonicator</td>
			<td style="width:135px;">Fisher Scientific</td>
			<td style="width:119px;">FB15051</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:291px;">Coverslips 24 x 50mm - No H1.5</td>
			<td style="width:135px;">Marienfeld</td>
			<td style="width:119px;">102222</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:291px;">DOPC</td>
			<td style="width:135px;">Avanti Polar Lipids</td>
			<td style="width:119px;">850357</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:291px;">Hellmanex III (detergent)</td>
			<td style="width:135px;">Hellma Analytics</td>
			<td style="width:119px;">320.003</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:291px;">Mica V-1 Grade</td>
			<td style="width:135px;">SPI Suppliers</td>
			<td style="width:119px;">1872-CA</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:291px;">Optical Adhesive (high viscosity)</td>
			<td style="width:135px;">Norland Products</td>
			<td style="width:119px;">NOA63</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:291px;">Optical Adhesive (low viscosity)</td>
			<td style="width:135px;">Norland Products</td>
			<td style="width:119px;">NOA60</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sphingomyelin-ATTO647N</td>
			<td style="width:135px;">AttoTec</td>
			<td>AD 647N-171</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:291px;">UV lamp</td>
			<td style="width:135px;">Synoptics Ltd.</td>
			<td style="width:119px;">GelVue GVM20</td>
			<td>The lamp was set to 100% power</td>
		</tr>
	</tbody>
</table>

preparation of mica supported lipid bilayers for high resolution optical microscopy imaging

Bicamadas lipídicas suportadas (EBSL) são amplamente utilizados como modelo para o estudo de propriedades da membrana (separação de fases, de agrupamento, dinâmica) e sua interação com outros compostos, tais como drogas ou peptídeos. No entanto características SLB diferente, dependendo do suporte utilizado. Técnicas comumente usados ​​para imagens e medições SLB são microscopia única molécula de fluorescência, FCS e microscopia de força atômica (AFM). Como a maioria dos estudos de imagiologia óptica são realizadas sobre um suporte de vidro, enquanto que a AFM requer uma superfície extremamente lisa (geralmente mica), os resultados destas técnicas não podem ser directamente comparados, uma vez que as propriedades de carga e de suavidade destes materiais influenciam fortemente a difusão. Infelizmente, o nível elevado de destreza manual necessária para o corte e colagem de fatias finas de mica para a lâmina de vidro apresenta um obstáculo para a utilização de rotina de mica para a preparação SLB. Embora este seja o método de escolha, tal mica preparadasuperfícies muitas vezes acabam por ser irregular (ondulado) e difícil de imagem, especialmente com distância de trabalho pequeno, lentes de alta abertura numérica. Aqui apresentamos um método simples e reprodutível para preparar superfícies planas finas de mica para a deposição de vesícula lipídica e preparação SLB. Além disso, a nossa câmara personalizado feito requer apenas pequenas quantidades de vesículas para a formação SLB. Os resultados do procedimento geral para a produção eficiente, simples e barata de alta qualidade superfícies da bicamada lipídica, que são directamente comparáveis ​​com os utilizados em estudos de AFM.

O comportamento de difusão de sondas fluorescentes lipídicas em EBSL é diferente, dependendo do substrato. TIRFM combinada com a técnica SMT é um método valioso para a visualização de movimentos de partículas e extrair os seus coeficientes de difusão. Sinais de moléculas isoladas de uma sonda de esfingomielina-ATTO647N difusão numa DOPC (1,2-dioleoil-sn-glicero-3-fosfocolina) em bicamada suportada em vidro e de mica são mostrados na figura animada em anexo. A superfície de mica foi preparado de ac...

Watch this Scientific Journal Video about Preparation of Mica Supported Lipid Bilayers for High Resolution Optical Microscopy Imaging at JoVE.com

Preparation of Mica Supported Lipid Bilayers for High Resolution Optical Microscopy Imaging

Apresenta-se um método de preparação de mica suportado bicamadas lipídicas para microscopia de alta resolução. Mica é transparente e liso em uma escala atômica, mas raramente usado em imagiologia por causa de dificuldades de manuseio; a preparação resulta em deposição uniforme da folha de mica, e reduz o material usado na preparação de bicamada.

Preparação de Mica Apoiado Lipid Bicamadas para alta resolução Microscopia Óptica de Imagem

Supported lipid bilayers (SLBs) are widely used as a model for studying membrane properties (phase separation, clustering, dynamics) and its interaction ...

preparation-mica-supported-lipid-bilayers-for-high-resolution-optical

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Bioengineering

13.3K visualizações.  Nanyang Technological University.  Apresenta-se um método de preparação de mica suportado bicamadas lipídicas para microscopia de alta resolução. Mica é transparente e liso em uma escala atômica, mas raramente usado em imagiologia por causa de dificuldades de manuseio; a preparação resulta em deposição uniforme da folha de mica, e reduz o material usado na preparação de bicamada. 

Vídeo: Preparation of Mica Supported Lipid Bilayers for High Resolution Optical Microscopy Imaging

High-resolution Fiber-optic Microendoscopy for in situ Cellular Imaging

Many biological and clinical studies require the longitudinal study and analysis of morphology and function with cellular level resolution. Traditionally, multiple experiments are run in parallel, with individual samples removed from the study at sequential time points for evaluation by light microscopy. Several intravital techniques have been developed, with confocal, multiphoton, and second harmonic microscopy all demonstrating their ability to be used for imaging in situ 1. With these systems, however, the required infrastructure is complex and expensive, involving scanning laser systems and complex light sources. Here we present a protocol for the design and assembly of a high-resolution microendoscope which can be built in a day using off-the-shelf components for under US$5,000. The platform offers flexibility in terms of image resolution, field-of-view, and operating wavelength, and we describe how these parameters can be easily modified to meet the specific needs of the end user.
We and others have explored the use of the high-resolution microendoscope (HRME) in in vitro cell culture 2-5, in excised 6 and living animal tissues 2,5, and in human tissues in vivo 2,7. Users have reported the use of several different fluorescent contrast agents, including proflavine 2-4, benzoporphyrin-derivative monoacid ring A (BPD-MA) 5, and fluoroscein 6,7, all of which have received full, or investigational approval from the FDA for use in human subjects. High-resolution microendoscopy, in the form described here, may appeal to a wide range of researchers working in the basic and clinical sciences. The technique offers an effective and economical approach which complements traditional benchtop microscopy, by enabling the user to perform high-resolution, longitudinal imaging in situ.

High-resolution Fiber-optic Microendoscopy for in situ Cellular Imaging

In many biological and clinical situations it is advantageous to study cellular processes as they evolve in their native microenvironment. Here we describe the assembly and use of a low-cost fiber-optic microscope which can provide real time imaging in cell culture, animal studies, and clinical patient studies.

De alta resolução de fibra óptica para Microendoscopy In situ Celular imagem

Many biological and clinical studies require the longitudinal study and analysis of morphology and function with cellular level resolution.  ...

Bioengenharia

Three-dimensional Optical-resolution Photoacoustic Microscopy

Optical microscopy, providing valuable insights at the cellular and organelle levels, has been widely recognized as an enabling biomedical technology. As the mainstays of in vivo three-dimensional (3-D) optical microscopy, single-/multi-photon fluorescence microscopy and optical coherence tomography (OCT) have demonstrated their extraordinary sensitivities to fluorescence and optical scattering contrasts, respectively. However, the optical absorption contrast of biological tissues, which encodes essential physiological/pathological information, has not yet been assessable. 
The emergence of biomedical photoacoustics has led to a new branch of optical microscopy optical-resolution photoacoustic microscopy (OR-PAM)1, where the optical irradiation is focused to the diffraction limit to achieve cellular1 or even subcellular2 level lateral resolution. As a valuable complement to existing optical microscopy technologies, OR-PAM brings in at least two novelties. First and most importantly, OR-PAM detects optical absorption contrasts with extraordinary sensitivity (i.e., 100%). Combining OR-PAM with fluorescence microscopy3 or with optical-scattering-based OCT4 (or with both) provides comprehensive optical properties of biological tissues. Second, OR-PAM encodes optical absorption into acoustic waves, in contrast to the pure optical processes in fluorescence microscopy and OCT, and provides background-free detection. The acoustic detection in OR-PAM mitigates the impacts of optical scattering on signal degradation and naturally eliminates possible interferences (i.e., crosstalks) between excitation and detection, which is a common problem in fluorescence microscopy due to the overlap between the excitation and fluorescence spectra. 
Unique for optical absorption imaging, OR-PAM has demonstrated broad biomedical applications since its invention, including, but not limited to, neurology5, 6, ophthalmology7, 8, vascular biology9, and dermatology10. In this video, we teach the system configuration and alignment of OR-PAM as well as the experimental procedures for in vivo functional microvascular imaging.

Optical-resolution photoacoustic microscopy (OR-PAM) is an emerging technology capable of imaging optical absorption contrasts in vivo with cellular resolution and sensitivity. Here, we provide a visualized instruction on the experimental protocols of OR-PAM, including system configuration, system alignment, typical in vivo experimental procedures, and functional imaging schemes.

Tridimensional Optical resolução Microscopia Fotoacústica

Optical microscopy, providing valuable insights at the cellular and organelle levels, has been widely recognized as an enabling biomedical technology. As ...

Wideband Optical Detector of Ultrasound for Medical Imaging Applications

Optical sensors of ultrasound are a promising alternative to piezoelectric techniques, as has been recently demonstrated in the field of optoacoustic imaging. In medical applications, one of the major limitations of optical sensing technology is its susceptibility to environmental conditions, e.g. changes in pressure and temperature, which may saturate the detection. Additionally, the clinical environment often imposes stringent limits on the size and robustness of the sensor. In this work, the combination of pulse interferometry and fiber-based optical sensing is demonstrated for ultrasound detection. Pulse interferometry enables robust performance of the readout system in the presence of rapid variations in the environmental conditions, whereas the use of all-fiber technology leads to a mechanically flexible sensing element compatible with highly demanding medical applications such as intravascular imaging. In order to achieve a short sensor length, a pi-phase-shifted fiber Bragg grating is used, which acts as a resonator trapping light over an effective length of 350 &#181;m. To enable high bandwidth, the sensor is used for sideway detection of ultrasound, which is highly beneficial in circumferential imaging geometries such as intravascular imaging. An optoacoustic imaging setup is used to determine the response of the sensor for acoustic point sources at different positions.

Optical detection of ultrasound is impractical in many imaging scenarios because it often requires stable environmental conditions. We demonstrate an optical technique for ultrasound sensing in volatile environments with miniaturization and sensitivity levels appropriate for optoacoustic imaging in restrictive scenarios, e.g. intravascular applications.

Wideband Detector óptico de ultra-som para aplicações Medical Imaging

Optical sensors of ultrasound are a promising alternative to piezoelectric techniques, as has been recently demonstrated in the field of optoacoustic ...

High-resolution Spatiotemporal Analysis of Receptor Dynamics by Single-molecule Fluorescence Microscopy

Single-molecule microscopy is emerging as a powerful approach to analyze the behavior of signaling molecules, in particular concerning those aspect (e.g., kinetics, coexistence of different states and populations, transient interactions), which are typically hidden in ensemble measurements, such as those obtained with standard biochemical or microscopy methods. Thus, dynamic events, such as receptor-receptor interactions, can be followed in real time in a living cell with high spatiotemporal resolution. This protocol describes a method based on labeling with small and bright organic fluorophores and total internal reflection fluorescence (TIRF) microscopy to directly visualize single receptors on the surface of living cells. This approach allows one to precisely localize receptors, measure the size of receptor complexes, and capture dynamic events such as transient receptor-receptor interactions. The protocol provides a detailed description of how to perform a single-molecule experiment, including sample preparation, image acquisition and image analysis. As an example, the application of this method to analyze two G-protein-coupled receptors, i.e., &#946;2-adrenergic and &#947;-aminobutyric acid type B (GABAB) receptor, is reported. The protocol can be adapted to other membrane proteins and different cell models, transfection methods and labeling strategies.

This protocol describes how to use total internal reflection fluorescence microscopy to visualize and track single receptors on the surface of living cells and thereby analyze receptor lateral mobility, size of receptor complexes as well as to visualize transient receptor-receptor interactions. This protocol can be extended to other membrane proteins.

De alta resolução espacial e temporal Análise de Receptor Dynamics por uma única molécula de microscopia de fluorescência

Single-molecule microscopy is emerging as a powerful approach to analyze the behavior of signaling molecules, in particular concerning those aspect (e.g., ...

Fluorescence-quenching of a Liposomal-encapsulated Near-infrared Fluorophore as a Tool for In Vivo Optical Imaging

Optical imaging offers a wide range of diagnostic modalities and has attracted a lot of interest as a tool for biomedical imaging. Despite the enormous number of imaging techniques currently available and the progress in instrumentation, there is still a need for highly sensitive probes that are suitable for in vivo imaging. One typical problem of available preclinical fluorescent probes is their rapid clearance in vivo, which reduces their imaging sensitivity. To circumvent rapid clearance, increase number of dye molecules at the target site, and thereby reduce background autofluorescence, encapsulation of the near-infrared fluorescent dye, DY-676-COOH in liposomes and verification of its potential for in vivo imaging of inflammation was done. DY-676 is known for its ability to self-quench at high concentrations. We first determined the concentration suitable for self-quenching, and then encapsulated this quenching concentration into the aqueous interior of PEGylated liposomes. To substantiate the quenching and activation potential of the liposomes we use a harsh freezing method which leads to damage of liposomal membranes without affecting the encapsulated dye. The liposomes characterized by a high level of fluorescence quenching were termed Lip-Q. We show by experiments with different cell lines that uptake of Lip-Q is predominantly by phagocytosis which in turn enabled the characterization of its potential as a tool for in vivo imaging of inflammation in mice models. Furthermore, we use a zymosan-induced edema model in mice to substantiate the potential of Lip-Q in optical imaging of inflammation in vivo. Considering possible uptake due to inflammation-induced enhanced permeability and retention (EPR) effect, an always-on liposome formulation with low, non-quenched concentration of DY-676-COOH (termed Lip-dQ) and the free DY-676-COOH were compared with Lip-Q in animal trials.

Fluorescence-quenching of a Liposomal-encapsulated Near-infrared Fluorophore as a Tool for In Vivo Optical Imaging

The use of fluorophores for in vivo imaging can be greatly limited by opsonization, rapid clearance, low detection sensitivity and cytotoxic effects on the host. Encapsulation of fluorophores in liposomes by film hydration and extrusion leads to fluorescence quenching and protection which enables in vivo imaging with high detection sensitivity.

Fluorescência-têmpera de um Fluoróforo encapsulado em lipossomas Near-infrared como ferramenta para<em&gt; In Vivo</em&gt; Imageamento óptico

Optical imaging offers a wide range of diagnostic modalities and has attracted a lot of interest as a tool for biomedical imaging. Despite the enormous ...

Atomic Force Microscopy Imaging and Force Spectroscopy of Supported Lipid Bilayers

Atomic force microscopy (AFM) is a versatile, high-resolution imaging technique that allows visualization of biological membranes. It has sufficient magnification to examine membrane substructures and even individual molecules. AFM can act as a force probe to measure interactions and mechanical properties of membranes. Supported lipid bilayers are conventionally used as membrane models in AFM studies. In this protocol, we demonstrate how to prepare supported bilayers and characterize their structure and mechanical properties using AFM. These include bilayer thickness and breakthrough force. 
The information provided by AFM imaging and force spectroscopy help define mechanical and chemical properties of membranes. These properties play an important role in cellular processes such as maintaining cell hemostasis from environmental stress, bringing membrane proteins together, and stabilizing protein complexes.

We describe a protocol for preparation of supported lipid bilayers and its characterization using atomic force microscopy and force spectroscopy.

Projeção de imagem atômica e força Espectroscopia de Bicamadas Lipídicas suportados

Atomic force microscopy (AFM) is a versatile, high-resolution imaging technique that allows visualization of biological membranes. It has sufficient ...

Single Molecule Fluorescence Microscopy on Planar Supported Bilayers

In the course of a single decade single molecule microscopy has changed from being a secluded domain shared merely by physicists with a strong background in optics and laser physics to a discipline that is now enjoying vivid attention by life-scientists of all venues 1. This is because single molecule imaging has the unique potential to reveal protein behavior in situ in living cells and uncover cellular organization with unprecedented resolution below the diffraction limit of visible light 2. Glass-supported planar lipid bilayers (SLBs) are a powerful tool to bring cells otherwise growing in suspension in close enough proximity to the glass slide so that they can be readily imaged in noise-reduced Total Internal Reflection illumination mode 3,4. They are very useful to study the protein dynamics in plasma membrane-associated events as diverse as cell-cell contact formation, endocytosis, exocytosis and immune recognition. Simple procedures are presented how to generate highly mobile protein-functionalized SLBs in a reproducible manner, how to determine protein mobility within and how to measure protein densities with the use of single molecule detection. It is shown how to construct a cost-efficient single molecule microscopy system with TIRF illumination capabilities and how to operate it in the experiment.

Preparation of protein-functionalized planar glass-supported lipid bilayers, determination of protein mobility within and measurement of protein densities is shown here. A roadmap to building a noise-reduced Total Internal Reflection microscope is outlined, which allows visualizing single bilayer-resident fluorochromes with high spatiotemporal resolution.

Bicamadas única molécula de microscopia de fluorescência em Planar Apoiado

In the course of a single decade single molecule microscopy has changed from being a secluded domain shared merely by physicists with a strong background ...

Ligand Nano-cluster Arrays in a Supported Lipid Bilayer

Currently there is considerable interest in creating ordered arrays of adhesive protein islands in a sea of passivated surface for cell biological studies. In the past years, it has become increasingly clear that living cells respond, not only to the biochemical nature of the molecules presented to them but also to the way these molecules are presented. Creating protein micro-patterns is therefore now standard in many biology laboratories; nano-patterns are also more accessible. However, in the context of cell-cell interactions, there is a need to pattern not only proteins but also lipid bilayers. Such dual proteo-lipidic patterning has so far not been easily accessible. We offer a facile technique to create protein nano-dots supported on glass and propose a method to backfill the inter-dot space with a supported lipid bilayer (SLB). From photo-bleaching of tracer fluorescent lipids included in the SLB, we demonstrate that the bilayer exhibits considerable in-plane fluidity. Functionalizing the protein dots with fluorescent groups allows us to image them and to show that they are ordered in a regular hexagonal lattice. The typical dot size is about 800 nm and the spacing demonstrated here is 2 microns. These substrates are expected to serve as useful platforms for cell adhesion, migration and mechano-sensing studies.

We present a protocol to functionalize glass with nanometric protein patches surrounded by a fluid lipid bilayer. These substrates are compatible with advanced optical microscopy and are expected to serve as platform for cell adhesion and migration studies.

Matrizes ligando Nano-fragmentação em uma bicamada lipídica Compatível

Currently there is considerable interest in creating ordered arrays of adhesive protein islands in a sea of passivated surface for cell biological ...

Switchable Acoustic and Optical Resolution Photoacoustic Microscopy for In Vivo Small-animal Blood Vasculature Imaging

Photoacoustic microscopy (PAM) is a fast-growing invivo imaging modality that combines both optics and ultrasound, providing penetration beyond the optical mean free path (~1 mm in skin) with high resolution. By combining optical absorption contrast with the high spatial resolution of ultrasound in a single modality, this technique can penetrate deep tissues. Photoacoustic microscopy systems can have either a low acoustic resolution and probe deeply or a high optical resolution and probe shallowly. It is challenging to achieve high spatial resolution and large depth penetration with a single system. This work presents an AR-OR-PAM system capable of both high-resolution imaging at shallow depths and low-resolution deep-tissue imaging of the same sample in vivo. A lateral resolution of 4 &#181;m with 1.4 mm imaging depth using optical focusing and a lateral resolution of 45 &#181;m with 7.8 mm imaging depth using acoustic focusing were successfully demonstrated using the combined system. Here,&#160;in vivo&#160;small-animal blood vasculature imaging is performed to demonstrate its biological imaging capability.

Switchable Acoustic and Optical Resolution Photoacoustic Microscopy for In Vivo Small-animal Blood Vasculature Imaging

Here a switchable acoustic resolution (AR) and optical resolution (OR) photoacoustic microscopy (AR-OR-PAM) system capable of both high resolution imaging at shallow depth and low resolution deep tissue imaging on the same sample in vivo is demonstrated.

Microscopia fotoacústica de resolução acústica e óptica comutável para<em&gt; In Vivo</em&gt; Imagem de Vasculatura de Sangue de Pequeno Animal

Photoacoustic microscopy (PAM) is a fast-growing invivo imaging modality that combines both optics and ultrasound, providing penetration beyond the ...

High Resolution 3D Imaging of the Human Pancreas Neuro-insular Network

Using traditional histological methods, researchers are hampered in their ability to image whole tissues or organs in large-scale 3D. Histological sections are generally limited to &#60;20 &#181;m as formalin fixed paraffin section on glass slides or &#60;500 &#181;m for free-floating fixed sections. Therefore, extensive efforts are required for serial sectioning and large-scale image reconstruction methods to recreate 3D for samples &#62;500 &#181;m using traditional methods. In addition, light scatters from macromolecules within tissues, particularly lipids, prevents imaging to a depth &#62;150 &#181;m with most confocal microscopes. To reduce light scatter and to allow for deep tissue imaging using simple confocal microscopy, various optical clearing methods have been developed that are relevant for rodent and human tissue samples fixed by immersion. Several methods are related and use protein crosslinking with acrylamide and tissue clearing with sodium dodecyl sulfate (SDS). Other optical clearing techniques used various solvents though each modification had various advantages and disadvantages. Here, an optimized passive optical clearing method is described for studies of the human pancreas innervation and specifically for interrogation of the innervation of human islets.

Here, we present a protocol to image human pancreas sections in three dimensions (3D) using optimized passive clearing methods. This manuscript demonstrates these procedures for passive optical clearing followed by multiple immunofluorescence staining to identify key elements of the autonomic and sensory neural networks innervating human islets.