Este projeto foi financiado pelo NIH / NINDS (# 1R01-NS54252), NSF (# 0905041, # 0079874), o Programa de Tecnologia Avançada do Texas (# ATP-000512-0146-2001, # ATP-000.512-0261-2001), Texas A &amp; M Research Foundation, Departamento de Ciência da Computação e Engenharia da Universidade Texas A &amp; M, e 3Scan. Gostaríamos de agradecer a Bernard Mesa (Micro Star Technologies) para consulta e apoio técnico para a instrumentação KESM. Partes principais do desenho e implementação do KESM foi feito por Bruce H. McCormick, que morreu em 2007.

1. Preparação de amostras: Golgi-Cox <ol><li> Este protocolo segue de perto o protocolo de Mayerich et al. 7. </li><li> O mouse C57BL/6J está profundamente anestesiados com anestesia inalatória com isoflurano e depois decapitado. </li><li> O cérebro é removido e colocado em uma solução de fixação Golgi-Cox (1% cromato de potássio, dicromato de potássio 1% e 1% de cloreto de mercúrio em água deionizada). </li><li> O cérebro é deixado na solução de Golgi-Cox no escuro, à temperatura ambiente, por 10 a 16 semanas. </li><li> Os cérebros são lavados em água deionizada durante a noite no escuro. </li><li> O cérebro lavado está imerso em solução a 5% de hidróxido de amónio em água deionizada por 7 a 10 dias no escuro à temperatura ambiente. Desta vez foi uma longa preparação para garantir a infiltração de todo o cérebro, para que o precipitado negro teve a chance de forma completamente no tecido. </li><li> O cérebro é lavado novamente em água deionizada à temperatura ambiente durante 4 horas e tgalinha desidratado através de uma série graduada de álcoois etílico: 50% e 70% na geladeira (4 ° C), e 85%, 95% (3 mudanças), e 100% (4-5 mudanças) em temperatura ambiente. O cérebro é deixado em cada solução por 24 horas. </li><li> O cérebro desidratado é então colocado em acetona (3 a 4 mudanças, cada um para um dia), seguido por uma mistura de araldite-acetona com araldite-to-acetona proporção de 1:2, 1:1, 2:1, e finalmente em 100% araldite (3 mudanças, cada vez que durante a noite), na geladeira (4 ° C). </li><li> Finalmente, o cérebro tratada é incorporado em araldite 100% e aquecido a 60 ° C durante 3 dias (cf. protocolo de incorporação, em Abbott e Sotelo 2). Se as amostras são incorporados em LR White então as amostras são transferidas da solução de etanol últimos 100% por três mudanças de LR solução Brancos que estão cada mantido no frigorífico durante a noite, que é um procedimento padrão antes da polimerização. Três mudanças são feitas para garantir a infiltração completa. A amostra é tgalinha transferidos para nova LR Branca que é polimerizado em um recipiente fechado a 60 ° C por 24 horas, que é a quantidade necessária de tempo e temperatura para a polimerização adequada. </li><li> Fig. 1 mostra um cérebro Golgi-Cox manchada embutido em Araldite. </li><li> O bloco da amostra curada é, então, montado no anel espécime de metal usando epoxy, e os lados do bloco aparadas, conforme necessário (ver fig. 2). </li></ol> 2. Preparação de amostras: Nissl <ol><li> O mouse está profundamente anestesiados com ketamina e xilazina (1,7 mg de cetamina / xilazina 0,26 mg por cada 20 gramas de peso corporal) por via intraperitoneal e então injetada perfundidos transcardially usando 50 mL de temperatura ambiente tampão fosfato (pH 7,4), seguido por 250 mL de quarto temperatura neutra a 10% tamponado (pH 7,4). e, finalmente, com 3,0 cc de tinta nanquim diluído. </li><li> Perfusão de corpo inteiro com solução salina e fixador é necessário para limpar o sangue do sistema cardiovascular e para fixar a ti<html> ssues. Perfusão com tinta nanquim é necessário para encher completamente a vasculatura do sistema cardiovascular. </li><li> O cérebro resultante é então desidratado através de uma série de álcoois graduados etílico (25% -100%) e depois incorporados em plástico araldite seguindo o protocolo em 1,8-1,9 acima. Se LR branco é o meio de incorporação, em seguida, o protocolo em 1.10 acima é seguido. </li></ol> 4. Preparação de amostras: Espécies genéricas, órgãos genéricos <ol><li> Para o caso genérico, a fixação pode ser feito tanto com paraformaldeído% 10% formalina tamponada neutra ou 4. </li><li> Para volumes pequenos de tecido, a difusão, em vez de perfusão é recomendada para fixação e coloração. No caso de pequenos organismos ou órgãos, coloração também pode ser feito durante o processo de desidratação. </li><li> O protocolo de incorporação é o mesmo que acima, embora os tempos de infiltração de solução pode ser reduzido para órgãos ou organismos que são muito menores do cérebro do rato inteiro. </li></ol>jove_title &quot;setup&gt; 5. KESM e imagem <ol><li> Desligue bomba, por sua vez no palco, por sua vez diante das câmeras, ligue iluminador. </li><li> Aumentar a faca e objetivo. </li><li> Instale o anel de amostra. </li><li> Dimensão medida exemplar e criar um arquivo de configuração para a aplicação Stage KESM Controller2. </li><li> Iniciar Stage KESM Controller2 e inicializar palco. </li><li> Inferior faca / objetiva, por sua vez na bomba. </li><li> Foco objetivo e câmera, girando o botão de focalização no trem óptica e ajuste de campo da câmera de vista em relação ao fio da navalha. </li><li> Pressione em [Continuar] para iniciar a imagem. </li><li> Ver Figs. 3-8. Veja 9, 7 de detalhes técnicos. </li></ol> 6. Processamento de imagem e preparação de dados <ol><li> Copie o executável KESM Processor Stack para a pasta de dados sob a pasta arquivo de configuração (00000, 00001, etc.) </li><li> Execute o processador KESM Stack para remover artefato de iluminação e normalizar a intensidade de fundo em todas asimagens. Repita o procedimento para todas as subpastas de dados. </li><li> Prepare telhas multiescala a partir do conjunto de dados e fazer o upload e configurar os arquivos no servidor web KESM Cérebro Atlas. </li><li> Ver fig. 9. </li></ol> 7. De visualização de dados e análise <ol><li> Visualização utilizando o Atlas Cerebral KESM. Ir para <a href="http://kesm.cs.tamu.edu">http://kesm.cs.tamu.edu</a> e selecione o atlas apropriado. <ol><li> Navegar como no Google Maps. </li><li> Zoom in e out como em mapas do Google. </li><li> Para ir a uma profundidade diferente, selecione o quão profundo para ir a cada passo a partir do menu pull-down, e clique em qualquer [+] ou [-] para aumentar ou diminuir a profundidade z. </li><li> Ajustar o número de sobreposição usando o menu suspenso. </li><li> Ajustar o intervalo de sobreposição usando o menu suspenso. </li><li> Ver fig. 11. </li></ol></li><li> Visualização usando MeVisLab. <ol><li> Lançamento MeVisLab. </li><li> Criar um novo projeto. </li><li> A seguir, novos módulos podem estar criando por typing no nome do módulo na caixa de comando. </li><li> Criar módulo [Compose3Dfrom2DFiles], e vá para a pasta desejada. Entra em seqüência arquivo e clique em [GetFileList]. Verifique se as imagens selecionadas podem caber na memória. Clique em [Create3D] para criar volume. </li><li> Criar módulo [SetWorldMatrix], e definir a &quot;escala&quot; em &quot;Elementary transformações&quot; x, y, z para o tamanho apropriado voxel (0,6, 0,7, 1,0 para a objetiva de 10x 0.45NA). Link [Compose3Dfrom2DFiles] para [SetWorldMatrix]. </li><li> Conjunto de Matrix e transforma em &quot;Composição Matrix&quot; a &quot;Ignore&quot;, &quot;Ignorar&quot;, &quot;Forward&quot;. </li><li> Criar módulo [Arithmetic1] e defina o &quot;Function&quot; para &quot;Inverter (Max-Img)&quot;. Link [SetWorldMatrix] para [Arithmetic1]. </li><li> Criar módulo [View3D] e ligar [Arithmetic1]. </li><li> Em View3D, enquanto o botão direito do mouse é pressionado, mova o mouse para ajustar o limite. Você pode cortar as regiões, mudança de orientação (mouse move enquanto o botão esquerdo do mouse é pressionado), iluminação mudança (renderin volume deg ou MIP), ligar / desligar de fundo, etc </li><li> Ver fig. 10. </li></ol></li></ol> 8. Resultados representativos: Aqui, apresentamos todo o cérebro de dados e detalhes. Figos. 15/12 show inteiro do cérebro India Ink, Golgi, e os dados de Nissl sets 1, 4, 3. <img alt="Figura 1" src="/files/ftp_upload/3248/3248fig1.jpg" /> Figura 1. Cérebro de camundongo fixo, manchado, e incorporados <img alt="Figura 2" src="/files/ftp_upload/3248/3248fig2.jpg" /> Figura 2. Espécime incorporado cérebro do rato montado no anel de amostra. <img alt="Figura 3" src="/files/ftp_upload/3248/3248fig3.jpg" /> Figura 3. Microscópio de varredura The Knife Edge (KESM). Uma foto da KESM é mostrado com seus principais componentes marcados: (1) de montagem faca linha de alta velocidade scan-câmera, (2) objetiva do microscópio (3), diamante e colimador de luz, (4) speCimen tanque (para imagens de imersão em água), (5) três eixos de precisão palco ao ar-rolamento (6), iluminador microscópio de luz branca (7), bomba de água (nas costas) para a remoção do tecido seccionado, (8) servidor PC para controle de estágio e de aquisição de imagem (9), base de granito, e (10) ponte de granito. <img alt="Figura 4" src="/files/ftp_upload/3248/3248fig4.jpg" /> Figura 4. Princípios de imagem do KESM. O diretor de operação da KESM é ilustrado. O objetivo ea faca é realizada no local, enquanto a amostra aposta no posicionamento move etapa (seta com linha sólida) na resolução de 20 nm ea velocidade de deslocamento de 1-5, e fica roçando a faca de diamante (5 mm de largura para objetiva de 10X), gerando uma seção fina que flui sobre a faca (seta com linha sólida). Linha-scan de imagens é feito perto da ponta da faca. <img alt="Figura 5" src="/files/ftp_upload/3248/3248fig5.jpg" /> Figura 5. Câmera KESM e objetiva controles de foco. <img alt="Figura 6" src="/files/ftp_upload/3248/3248fig6.jpg" /> Figura 6. KESM montagem faca e controles. <img alt="Figura 7" src="/files/ftp_upload/3248/3248fig7.jpg" /> Figura 7. Foco inicial através da porta de observação. <img alt="Figura 8" src="/files/ftp_upload/3248/3248fig8.jpg" /> Figura 8. KESM Controlador de Fase 2 do aplicativo (screenshot). <img alt="Figura 9" src="/files/ftp_upload/3248/3248fig9.jpg" /> Figura 9. KESM processador de pilha (screenshot). <img alt="Figura 10" src="/files/ftp_upload/3248/3248fig10.jpg" /> Figura 10. MeVisLab aplicação (screenshot). <img alt="Figura 11" src="/files/ftp_upload/3248/3248fig11.jpg" /><br/&gt; Figura 11 KESM Cérebro Atlas:. Interface Web (screenshot). <img alt="Figura 12" src="/files/ftp_upload/3248/3248fig12.jpg" /> Figura 12. KESM todo o cérebro dados tinta nanquim. Visualizações volume de pilhas de dados KESM são mostradas para o conjunto de dados vascular. (A) Close-up dos dados vascular. Largura ~ 100 um. (Bd) Três vistas padrão de toda a vasculatura cerebral do rato (subsampled de dados de alta resolução). Largura ~ 10mm. <img alt="Figura 13" src="/files/ftp_upload/3248/3248fig13.jpg" /> Figura 13. KESM todo o cérebro dados do mouse Golgi. <img alt="Figura 14" src="/files/ftp_upload/3248/3248fig14.jpg" /> Figura 14. KESM detalhes Golgi dados. <img alt="Figura 15" src="/files/ftp_upload/3248/3248fig15.jpg" /> Figura 15. KESM todo o cérebro dados Nissl. (A) Close-up do Ndados ISSL. ~ Hum 300 3. (Bd) Três vistas padrão do conjunto de dados do mouse cérebro Nissl (subsampled de dados de alta resolução). Seção transversal mostrada para uma visão clara das estruturas internas.

<ol>
	<li>Abbott, L. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-throughput+imaging+of+whole+small+animal+brains+with+the+knife-edge+scanning+microscope.">High-throughput imaging of whole small animal brains with the knife-edge scanning microscope.</a> Neuroscience Meeting Planner. Program No. 504.2, (2008).</li><li>Abbott, L. C., Sotelo, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrastructural+analysis+of+catecholaminergic+innervation+in+weaver+and+normal+mouse+cerebellar+cortices.">Ultrastructural analysis of catecholaminergic innervation in weaver and normal mouse cerebellar cortices.</a> Journal of Comparative Neurology. 426, 316-329 (2000).</li><li>Choe, Y., Abbott, L. C., Miller, D. E., Han, D., Yang, H. -. F., Chung, J. R., Sung, C., Mayerich, D., Kwon, J., Micheva, K., Smith, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multiscale+imaging,+analysis,+and+integration+of+mouse+brain+networks.">Multiscale imaging, analysis, and integration of mouse brain networks.</a> Neuroscience Meeting Planner. Program No. 516.3, (2010).</li><li>Choe, Y., Han, D., Huang, P. -. S., Keyser, J., Kwon, J., Mayerich, D., Abbott, L. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Complete+submicrometer+scans+of+mouse+brain+microstructure:+Neurons+and+vasculatures.">Complete submicrometer scans of mouse brain microstructure: Neurons and vasculatures.</a> Neuroscience Meeting Planner. Program No. 389.10, (2009).</li><li>Choe, Y., Abbott, L. C., Han, D., Huang, P. S., Keyser, J., Kwon, J., Mayerich, D., Melek, Z., McCormick, B. H., Ravi Rao, A., Cecchi, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Knife-edge+scanning+microscopy:+High-throughput+imaging+and+analysis+of+massive+volumes+of+biological+microstructures.">Knife-edge scanning microscopy: High-throughput imaging and analysis of massive volumes of biological microstructures.</a> High-Throughput Image Reconstruction and Analysis: Intelligent Microscopy Applications. , 11-37 (2008).</li><li>Choe, Y., Abbott, L. C., Ponte, G., Keyser, J., Kwon, J., Mayerich, D., Miller, D., Han, D., Grimaldi, A. M., Fiorito, F., Edelman, D. B., McKinstry, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Charting+out+the+octopus+connectome+at+submicron+resolution+using+the+knife-edge+scanning+microscope.">Charting out the octopus connectome at submicron resolution using the knife-edge scanning microscope.</a> BMC Neuroscience. 11, 136-136 (2010).</li><li>Mayerich, D., Abbott, L. C., McCormick, B. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Knife-edge+scanning+microscopy+for+imaging+and+reconstruction+of+three-dimensional+anatomical+structures+of+the+mouse+brain.">Knife-edge scanning microscopy for imaging and reconstruction of three-dimensional anatomical structures of the mouse brain.</a> Journal of Microscopy. 231, 134-143 (2008).</li><li>Mayerich, D., Kwon, J., Sung, C., Abbott, L. C., Keyser, J., Choe, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fast+macro-scale+Transmission+Imaging+of+Microvascular+Networks+Using+KESM.">Fast macro-scale Transmission Imaging of Microvascular Networks Using KESM.</a> Biomedical Optics Express. 2, 2888-2896 (2008).</li><li>McCormick, B. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+the+Brain+Tissue+Scanner.">Development of the Brain Tissue Scanner.</a> Technical Report. , (2002).</li><li>Sporns, O., Tononi, G., K&#246;tter, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+human+connectome:+A+structural+description+of+the+human+brain.">The human connectome: A structural description of the human brain.</a> PLoS Computational Biology. 1, 42-42 (2005).</li></ol>

Todd Huffman é com 3Scan, uma empresa comercial que fabrica e comercializa a tecnologia KESM (EUA patente # 6744572).

O KESM permite um levantamento submicrometer nível de grandes volumes de amostra biológica (~ 1 cm 3). Este tipo de volume é suficiente para manter toda órgãos de animais pequenos, tais como cérebro, pulmões, corações, rins, etc digitalizadas imagens de órgãos como pode fornecer informações quantitativas sem precedentes sobre a organização estrutural destes órgãos, e permitir a modelagem computacional de funcionais diversas aspectos desses órgãos, incluindo circuito e de rede dinâmica, propriedades elétricas, fluida e dinâmica de fluxo de ar, ea dinâmica muscular. O protocolo de preparação de amostras e análise pós-protocolo detalhado neste artigo são esperados para ajudar grupos de pesquisa de fora para ter acesso mais fácil ao KESM e os dados resultantes. O protocolo de operação KESM ajudará esses pesquisadores externos para apreciar os benefícios e limitações desta modalidade de imagem única.

A correction was made to <a href="http://www.jove.com/video/3248">Specimen Preparation, Imaging, and Analysis Protocols for Knife-edge Scanning Microscopy</a>. Important modifications were made to the Nissl staining protocol.

A correction was made to <a href="http://http://www.jove.com/video/3248">Specimen Preparation, Imaging, and Analysis Protocols for Knife-edge Scanning Microscopy</a>. Important modifications were made to the Nissl staining protocol.

Erratum: Specimen Preparation, Imaging, and Analysis Protocols for Knife-edge Scanning Microscopy

specimen preparation, imaging, and analysis protocols for knife-edge scanning microscopy

Grandes avanços no alto rendimento, alta resolução, técnicas de microscopia em 3D permitiram a aquisição de grandes volumes de dados neuroanatômicos na resolução submicrometer. Um dos primeiros instrumentos tais produzir todo o cérebro de dados em escala é o microscópio de varredura Knife Edge (KESM) 7, 5, 9, desenvolvido e hospedado no laboratório dos autores. KESM tem sido usado para seção e cérebros imagem inteira do mouse em resolução submicrometer, revelando os detalhes intrincados das redes neuronais (Golgi) 1, 4, 8, as redes vascular (tinta nanquim) 1, 4 e distribuição das células do corpo (Nissl) 3 . O uso de KESM não se restringe ao mouse nem o cérebro. Conseguimos imaged o cérebro do polvo 6, pulmão do rato, e no cérebro de ratos. Estamos atualmente trabalhando em embriões de peixe zebra inteira. Dados como estes podem contribuir enormemente para a pesquisa conectonomia 10; a microcirculação e pesquisa hemodinâmica; e pesquisar por estereologia providing um. exata chão verdade Neste artigo, vamos descrever o pipeline, incluindo a preparação de amostras (fixação, coloração, e incorporação), KESM configuração e instalação, de corte e de imagem com o KESM, processamento de imagem, preparação de dados e visualização de dados e análise. A ênfase será sobre a preparação de amostras e visualização / análise de dados obtidos KESM. Esperamos que o protocolo detalhado apresentado neste artigo para ajudar a ampliar o acesso a KESM e aumentar a sua utilização.

Watch this Scientific Journal Video about Specimen Preparation, Imaging, and Analysis Protocols for Knife-edge Scanning Microscopy at JoVE.com

Specimen Preparation, Imaging, and Analysis Protocols for Knife-edge Scanning Microscopy

Todo o processo de preparação de amostras de imagens do cérebro para o seccionamento serial usando o microscópio de varredura Knife Edge, para visualização e análise de dados é descrito. Esta técnica é usada atualmente para adquirir dados cérebro do rato, mas é aplicável a outros órgãos, outras espécies.

Preparação de amostras, Imaging, and Analysis Protocolos para Faca de ponta microscopia de varredura

Major advances in high-throughput, high-resolution, 3D microscopy techniques have enabled the acquisition of large volumes of neuroanatomical data at ...

specimen-preparation-imaging-analysis-protocols-for-knife-edge

Research

JoVE Journal

Bioengineering

17.5K visualizações.  Texas A&M University. Todo o processo de preparação de amostras de imagens do cérebro para o seccionamento serial usando o microscópio de varredura Knife Edge, para visualização e análise de dados é descrito. Esta técnica é usada atualmente para adquirir dados cérebro do rato, mas é aplicável a outros órgãos, outras espécies.

Vídeo: Specimen Preparation, Imaging, and Analysis Protocols for Knife-edge Scanning Microscopy

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 ...

Bioengenharia

Bacterial Immobilization for Imaging by Atomic Force Microscopy

AFM is a high-resolution (nm scale) imaging tool that mechanically probes a surface. It has the ability to image cells and biomolecules, in a liquid environment, without the need to chemically treat the sample. In order to accomplish this goal, the sample must sufficiently adhere to the mounting surface to prevent removal by forces exerted by the scanning AFM cantilever tip. In many instances, successful imaging depends on immobilization of the sample to the mounting surface. Optimally, immobilization should be minimally invasive to the sample such that metabolic processes and functional attributes are not compromised. By coating freshly cleaved mica surfaces with porcine (pig) gelatin, negatively charged bacteria can be immobilized on the surface and imaged in liquid by AFM. Immobilization of bacterial cells on gelatin-coated mica is most likely due to electrostatic interaction between the negatively charged bacteria and the positively charged gelatin. Several factors can interfere with bacterial immobilization, including chemical constituents of the liquid in which the bacteria are suspended, the incubation time of the bacteria on the gelatin coated mica, surface characteristics of the bacterial strain and the medium in which the bacteria are imaged. Overall, the use of gelatin-coated mica is found to be generally applicable for imaging microbial cells.

Live Gram-negative and Gram-positive bacteria can be immobilized on gelatin-coated mica and imaged in liquid using Atomic Force Microscopy (AFM).

A imobilização de bactérias for Imaging por Microscopia de Força Atômica

AFM is a high-resolution (nm scale) imaging tool that mechanically probes a surface.  It has the ability to image cells and biomolecules, in a liquid ...

Video-rate Scanning Confocal Microscopy and Microendoscopy

Confocal microscopy has become an invaluable tool in biology and the biomedical sciences, enabling rapid, high-sensitivity, and high-resolution optical sectioning of complex systems. Confocal microscopy is routinely used, for example, to study specific cellular targets1, monitor dynamics in living cells2-4, and visualize the three dimensional evolution of entire organisms5,6. Extensions of confocal imaging systems, such as confocal microendoscopes, allow for high-resolution imaging in vivo7 and are currently being applied to disease imaging and diagnosis in clinical settings8,9.
Confocal microscopy provides three-dimensional resolution by creating so-called "optical sections" using straightforward geometrical optics. In a standard wide-field microscope, fluorescence generated from a sample is collected by an objective lens and relayed directly to a detector. While acceptable for imaging thin samples, thick samples become blurred by fluorescence generated above and below the objective focal plane. In contrast, confocal microscopy enables virtual, optical sectioning of samples, rejecting out-of-focus light to build high resolution three-dimensional representations of samples.
Confocal microscopes achieve this feat by using a confocal aperture in the detection beam path. The fluorescence collected from a sample by the objective is relayed back through the scanning mirrors and through the primary dichroic mirror, a mirror carefully selected to reflect shorter wavelengths such as the laser excitation beam while passing the longer, Stokes-shifted fluorescence emission. This long-wavelength fluorescence signal is then passed to a pair of lenses on either side of a pinhole that is positioned at a plane exactly conjugate with the focal plane of the objective lens. Photons collected from the focal volume of the object are collimated by the objective lens and are focused by the confocal lenses through the pinhole. Fluorescence generated above or below the focal plane will therefore not be collimated properly, and will not pass through the confocal pinhole1, creating an optical section in which only light from the microscope focus is visible. (Fig 1). Thus the pinhole effectively acts as a virtual aperture in the focal plane, confining the detected emission to only one limited spatial location.
Modern commercial confocal microscopes offer users fully automated operation, making formerly complex imaging procedures relatively straightforward and accessible. Despite the flexibility and power of these systems, commercial confocal microscopes are not well suited for all confocal imaging tasks, such as many in vivo imaging applications. Without the ability to create customized imaging systems to meet their needs, important experiments can remain out of reach to many scientists.
In this article, we provide a step-by-step method for the complete construction of a custom, video-rate confocal imaging system from basic components. The upright microscope will be constructed using a resonant galvanometric mirror to provide the fast scanning axis, while a standard speed resonant galvanometric mirror will scan the slow axis. To create a precise scanned beam in the objective lens focus, these mirrors will be positioned at the so-called telecentric planes using four relay lenses. Confocal detection will be accomplished using a standard, off-the-shelf photomultiplier tube (PMT), and the images will be captured and displayed using a Matrox framegrabber card and the included software.

The complete construction of a custom, real-time confocal scanning imaging system is described. This system, which can be readily used for video-rate microscopy and microendoscopy, allows for an array of imaging geometries and applications not accessible using standard commercial confocal systems, at a fraction of the cost.

Vídeo taxa de microscopia de varredura confocal e Microendoscopy

Confocal microscopy has become an invaluable tool in biology and the biomedical sciences, enabling rapid, high-sensitivity, and high-resolution optical ...

Creating Adhesive and Soluble Gradients for Imaging Cell Migration with Fluorescence Microscopy

Cells can sense and migrate towards higher concentrations of adhesive cues such as the glycoproteins of the extracellular matrix and soluble cues such as growth factors. Here, we outline a method to create opposing gradients of adhesive and soluble cues in a microfluidic chamber, which is compatible with live cell imaging. A copolymer of poly-L-lysine and polyethylene glycol (PLL-PEG) is employed to passivate glass coverslips and prevent non-specific adsorption of biomolecules and cells. Next, microcontact printing or dip pen lithography are used to create tracks of streptavidin on the passivated surfaces to serve as anchoring points for the biotinylated peptide arginine-glycine-aspartic acid (RGD) as the adhesive cue. A microfluidic device is placed onto the modified surface and used to create the gradient of adhesive cues (100% RGD to 0% RGD) on the streptavidin tracks. Finally, the same microfluidic device is used to create a gradient of a chemoattractant such as fetal bovine serum (FBS), as the soluble cue in the opposite direction of the gradient of adhesive cues.

A method for the assembly of adhesive and soluble gradients in a microscopy chamber for live cell migration studies is described. The engineered environment combines antifouling surfaces and adhesive tracks with solution gradients and therefore allows one to determine the relative importance of guidance cues.

Criando Gradientes adesivas e solúvel para a migração celular Imaging com Microscopia de Fluorescência

Cells can sense and migrate towards higher concentrations of adhesive cues such as the glycoproteins of the extracellular matrix and soluble cues such as ...

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., ...

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

Supported lipid bilayers (SLBs) are widely used as a model for studying membrane properties (phase separation, clustering, dynamics) and its interaction with other compounds, such as drugs or peptides. However SLB characteristics differ depending on the support used. 
Commonly used techniques for SLB imaging and measurements are single molecule fluorescence microscopy, FCS and atomic force microscopy (AFM). Because most optical imaging studies are carried out on a glass support, while AFM requires an extremely flat surface (generally mica), results from these techniques cannot be compared directly, since the charge and smoothness properties of these materials strongly influence diffusion. Unfortunately, the high level of manual dexterity required for the cutting and gluing thin slices of mica to the glass slide presents a hurdle to routine use of mica for SLB preparation. Although this would be the method of choice, such prepared mica surfaces often end up being uneven (wavy) and difficult to image, especially with small working distance, high numerical aperture lenses. Here we present a simple and reproducible method for preparing thin, flat mica surfaces for lipid vesicle deposition and SLB preparation. Additionally, our custom made chamber requires only very small volumes of vesicles for SLB formation. The overall procedure results in the efficient, simple and inexpensive production of high quality lipid bilayer surfaces that are directly comparable to those used in AFM studies.

We present a method of preparing mica supported lipid bilayers for high resolution microscopy. Mica is transparent and flat on an atomic scale, but rarely used in imaging because of handling difficulties; our preparation results in even deposition of the mica sheet, and reduces the material used in bilayer preparation.

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 ...

Hybrid &#181;CT-FMT imaging and image analysis

Fluorescence-mediated tomography (FMT) enables longitudinal and quantitative determination of the fluorescence distribution in vivo and can be used to assess the biodistribution of novel probes and to assess disease progression using established molecular probes or reporter genes. The combination with an anatomical modality, e.g., micro computed tomography (&#181;CT), is beneficial for image analysis and for fluorescence reconstruction. We describe a protocol for multimodal &#181;CT-FMT imaging including the image processing steps necessary to extract quantitative measurements. After preparing the mice and performing the imaging, the multimodal data sets are registered. Subsequently, an improved fluorescence reconstruction is performed, which takes into account the shape of the mouse. For quantitative analysis, organ segmentations are generated based on the anatomical data using our interactive segmentation tool. Finally, the biodistribution curves are generated using a batch-processing feature. We show the applicability of the method by assessing the biodistribution of a well-known probe that binds to bones and joints.

Hybrid  &amp;#181;CT-FMT imaging and image analysis

We describe a protocol for hybrid imaging, combining fluorescence-mediated tomography (FMT) with micro computed tomography (&#181;CT). After fusion and reconstruction, we perform interactive organ segmentation to extract quantitative measurements of the fluorescence distribution.

Híbrido de imagem μCT-FMT e análise de imagem

Fluorescence-mediated tomography (FMT) enables longitudinal and quantitative determination of the fluorescence distribution in vivo and can be used to ...

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 ...

Correlative Light Electron Microscopy (CLEM) for Tracking and Imaging Viral Protein Associated Structures in Cryo-immobilized Cells

Due to its high resolution, electron microscopy (EM) is an indispensable tool for virologists. However, one of the main difficulties when analyzing virus-infected or transfected cells via EM are the low efficiencies of infection or transfection, hindering the examination of these cells. In order to overcome this difficulty, light microscopy (LM) can be performed first to allocate the subpopulation of infected or transfected cells. Thus, taking advantage of the use of fluorescent proteins (FPs) fused to viral proteins, LM is used here to record the positions of the "positive-transfected" cells, expressing a FP and growing on a support with an alphanumeric pattern. Subsequently, cells are further processed for EM via high pressure freezing (HPF), freeze substitution (FS) and resin embedding. The ultra-rapid freezing step ensures excellent membrane preservation of the selected cells that can then be analyzed at the ultrastructural level by transmission electron microscopy (TEM). Here, a step-by-step correlative light electron microscopy (CLEM) workflow is provided, describing sample preparation, imaging and correlation in detail. The experimental design can be also applied to address many cell biology questions.

Correlative Light Electron Microscopy CLEM for Tracking and Imaging Viral Protein Associated Structures in Cryo-immobilized Cells

A correlative light electron microscopy (CLEM) method is applied to image virus-induced intracellular structures via electron microscopy (EM) in cells that are previously selected by light microscopy (LM). LM and EM are combined as a hybrid imaging approach to achieve an integrated view of virus-host interactions.

Correlativo luz microscopia eletrônica de varredura (CLEM) para rastreamento e Imaging proteína Viral associado estruturas nas células Cryo-imobilizado

Due to its high resolution, electron microscopy (EM) is an indispensable tool for virologists. However, one of the main difficulties when analyzing ...

Visualizing Adhesion Formation in Cells by Means of Advanced Spinning Disk-Total Internal Reflection Fluorescence Microscopy

In living cells, processes such as adhesion formation involve extensive structural changes in the plasma membrane and the cell interior. In order to visualize these highly dynamic events, two complementary light microscopy techniques that allow fast imaging of live samples were combined: spinning disk microscopy (SD) for fast and high-resolution volume recording and total internal reflection fluorescence (TIRF) microscopy for precise localization and visualization of the plasma membrane. A comprehensive and complete imaging protocol will be shown for guiding through sample preparation, microscope calibration, image formation and acquisition, resulting in multi-color SD-TIRF live imaging series with high spatio-temporal resolution. All necessary image post-processing steps to generate multi-dimensional live imaging datasets, i.e. registration and combination of the individual channels, are provided in a self-written macro for the open source software ImageJ. The imaging of fluorescent proteins during initiation and maturation of adhesion complexes, as well as the formation of the actin cytoskeletal network, was used as a proof of principle for this novel approach. The combination of high resolution 3D microscopy and TIRF provided a detailed description of these complex processes within the cellular environment and, at the same time, precise localization of the membrane-associated molecules detected with a high signal-to-background ratio.

An advanced microscope that permit fast and high-resolution imaging of both, the isolated plasma membrane and the surrounding intracellular volume, will be presented. The integration of spinning disk and total internal reflection fluorescence microscopy in one setup allows live imaging experiments at high acquisition rates up to 3.5 s per image stack.

Visualizando a formação de adesão em células por meio de avançados girando a reflexão interna Total disco microscopia de fluorescência

In living cells, processes such as adhesion formation involve extensive structural changes in the plasma membrane and the cell interior. In order to ...