Agradecemos Jianhua Ling, Raymond MacDonald, Galvin Swift, Michelle Griffin, Paul Grippo e Satyanarayana Rachagani por seus comentários úteis, sugestões e partilha de seus protocolos. Este trabalho foi apoiado por U01CA111294 concessão e um Prêmio Idea Desenvolvimento do Programa de Pesquisa intramuros Ohio State University.

1. Preparação As seguintes práticas aderir às políticas estabelecidas pelo Animal Care and Use Committee da Instituição (IACUC). <ol><li> Recomenda-se a isolar não mais de 6 pâncreas do rato em qualquer dia. Tenha todos os instrumentos cirúrgicos limpos e autoclavados, um conjunto por animal. </li><li> Rotular todos os microtubos. Quatro tubos de 2 ml por animal. </li><li> Colocar 8 ml de reagente de lise em 50 ml de tubos de centrífuga em gelo. Nota: Embora o kit de purificação trata com um reagente fenol de tiocianato de guanidina, que é adequado para o isolamento de pâncreas, de reagente de lise é usado por causa dos grandes volumes de que são necessárias por isolamento. </li><li> Dispensar cerca de 10 ml das seguintes soluções em tubos de centrífuga de 15 ml para a limpeza lâminas do homogeneizador. O etanol, 70% (2 tubos), HPLC água (1 tubo) e água de grau HPLC, contendo cerca de 200 mL de RNase afastado ou inativador ribonuclease equivalente. </li></ol&gt; 2. Cirurgia, Dissection Pâncreas e homogeneização <ol><li> Coloque 1-2 ml de isoflurano em um frasco contendo gaze de algodão ou toalhas de papel. Os ratos são colocados numa plataforma que os impede de se atingir a fonte de isoflurano. Adicionar isoflurano fresco para o frasco antes de anestesiar cada rato. </li><li> Delicadamente, coloque o mouse no frasco contendo o isoflurano. Tampe o frasco e monitorar os efeitos da anestesia, rodando suavemente o frasco e para trás. O animal é anestesiado, uma vez que está na incapaz de ficar na sua &quot;própria. </li><li> Para confirmação da anestesia, remover o animal do frasco e aplicar uma pitada do dedo do pé firme. Se o mouse não reagir ao aperto do dedo do pé, vá para o passo 2.5. </li><li> Se o rato reage ao pitada dedo do pé, em seguida, repita os passos de 2,2-2,3. </li><li> Colocar o animal anestesiado na bancada na posição prona. Deslocar colo do rato por força colocando a mão esquerda no colo do mouse. Nósção da mão direita agarrar a cauda do rato e rapidamente puxar para cima em um ângulo de aproximadamente 45 ° para deslocar o colo do útero. </li><li> Fixe a carcaça a uma superfície (um pedaço de isopor nível de cobertas com toalhas de papel), perfurando cada uma das quatro patas do animal na superfície plana usando calibre 25 agulhas hipodérmicas. </li><li> Usando instrumentos cirúrgicos estéreis, corte o meio do mouse aberta e rapidamente remover o pâncreas do mouse. Use a pinça para segurar o pâncreas e cortá-la a partir do baço e do intestino delgado com uma tesoura de mola. Tenha cuidado para não esticar o pâncreas durante a remoção do mouse. O rompimento do tecido poderia liberar ribonuclease. Nota: O tempo que leva a remover o pâncreas do rato é crítica. Um perito deve ser capaz de dissecar o pâncreas em cerca de um minuto ou menos. </li><li> Colocar todo o pâncreas para um tubo de 50 ml contendo 8 ml de reagente de lise frio de gelo. Tampe o tubo e agitar brevemente para imergir o tissue no reagente e avançar para o próximo passo sem demora. A proporção de reagente de lise de tecido é crítica. Ver secção de resultados de uma comparação entre a integridade do RNA isolado utilizando diferentes volumes de reagente de lise. </li><li> Homogeneizar por 5 seg. É importante para pressionar as lâminas homogeneizador para o fundo do tubo de centrífuga para permitir que o tecido seja puxado para dentro das lâminas para homogenização eficiente. </li></ol> 3. Remoção de tecido não digerido Nota: Após a homogeneização, pequenos pedaços de tecido permanecem no reagente de lise. É mais importante para lisar rapidamente o tecido deixando um pouco de tecido não digerido, em vez de ao longo de homogeneização e degradação risco de RNA. <ol><li> Transferência de 2 ml de reagente de lise contendo o pâncreas lisadas para um tubo de microcentrífuga de 2 ml. Colete dois microtubos de homogeneizado por isolamento. Descarte o homogeneizado restante ou armazenar a -80 ° C para estudos futuros. </li><li> Centavorifuge a 4 ° C, 12000 g durante 5 min para sedimentar o tecido não digerido. Este é um passo crítico como transição de tecido não digerido em soluções posteriores de RNA provavelmente vai contaminar a amostra com ribonuclease (passo 5.13). </li><li> Transferir 1 ml do sobrenadante para um tubo de microcentrifugação de 2 ml. Prosseguir com o isolamento imediatamente e armazenar o tubo de replicar-se a -80 ° C para uso futuro. Coloque todos os tubos contendo homogeneizado em gelo molhado enquanto prosseguir para a próxima etapa. </li><li> Descarte o reagente de lise restante em um recipiente de lixo químico apropriado. </li></ol> 4. Limpeza dos Blades homogeneizador <ol><li> Antes de prosseguir para o próximo isolamento, limpeza das lâminas homogeneizador, colocando-os em 10 ml de etanol a 70%. Ative o homogeneizador por cerca de 20 segundos para remover quaisquer pedaços de tecido que podem ser capturados nas lâminas. </li><li> Use uma ponta de 200 mL da pipeta para remover quaisquer peças que permanecem nas lâminas homogeneizador. </li&gt; <li> Repita o passo 4.1 na água, inativador geral Rnase e 70% de etanol. Seque o eixo com um homogeneizador de Kim limpo limpar. </li><li> Repetir o passo 2.1 para o isolamento pâncreas dos animais restantes, mantendo RNA isolado a partir de cada animal, em vez de separar o pool de RNA. </li></ol> 5. Isolamento de ARN A secção que se segue é idêntico ao protocolo do kit de purificação. A vantagem do kit de purificação é que vai isolar o ARN total, incluindo pequenos RNAs. <ol><li> Se estiver usando solução homogeneizado congelado, descongelar no gelo molhado e deixe descansar em temperatura ambiente por 5 min. </li><li> Adicionar 200 mL de clorofórmio, tampar o tubo e agitar vigorosamente à mão por 15 segundos. Deixe o tubo repousar à temperatura ambiente durante 2-3 minutos. </li><li> Centrifugar durante 15 minutos a 12.000 xg, a 4 ° C. </li><li> Transferir a fase aquosa superior para um tubo de microcentrífuga. Adicionar 1,5 volumes de isopropanol e misture bem por pipetagem cima e para baixo várias vezes. </li><li> Transfira até 700 ul da amostra em uma coluna de rotação que é colocada num tubo de recolha de 2 ml. Fechar a tampa e centrifugar a 8000 g durante 15 segundos à temperatura ambiente. </li><li> Descartar o escoamento. </li><li> Repita os passos de 5,5-5,6, utilizando-se o restante da amostra. </li><li> Adicionar 700 mL de buffer ERP para a coluna de centrifugação. Centrifugar durante 15 segundos a 8.000 x g. Descartar o escoamento. </li><li> Pipetar 500 mL de buffer RPE na coluna de rotação. Centrifugar durante 15 segundos a 8000 x g para lavar a coluna. Descartar o escoamento. </li><li> Adicionar 500 mL de buffer RPE para a coluna de centrifugação. Centrifugar durante 2 minutos a 8.000 xg, para secar a coluna. </li><li> Transferir a coluna de centrifugação para um tubo de microcentrífuga de 1,5 ml. Pipetar 80 mL sem ribonuclease água diretamente sobre a membrana coluna rodada. Centrifugar durante 1 minuto a 8.000 xg, para eluir o ARN. </li><li> Adicionar 1 mL inibidor de RNase à solução de ARN. Armazenar a -80 ° C ou prosseguir para 5.13. </li><li> Para validar a integridade do RNA, primeiro calcular o conce RNAntration e 260/280 escala utilizando um espectrofotômetro. </li><li> Dilui-se uma porção da solução de RNA de cerca de 500 ng / mL com água de grau de biologia molecular. </li><li> Determinar a integridade de ARN (isto é, RIN) usando a análise de electroforese capilar. Cerca de 5 ul da solução de RNA é suficiente para a análise. </li><li> Alíquota da solução de RNA (ver Figura 2) e armazenar a -80 ° C. </li></ol>

<ol>
	<li>Chen, C., Ridzon, D. A., Broomer, A. J., Zhou, Z., Lee, D. H., Nguyen, J. T., Barbisin, M., Xu, N. L., Mahuvakar, V. R., Andersen, M. R., 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=Real-time+quantification+of+microRNAs+by+stem-loop+RT-PCR.">Real-time quantification of microRNAs by stem-loop RT-PCR.</a> Nucleic Acids Res. 33, e179 (2005).</li><li>Chirgwin, J. M., Przybyla, A. E., MacDonald, R. J., Rutter, W. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+of+biologically+active+ribonucleic+acid+from+sources+enriched+in+ribonuclease.">Isolation of biologically active ribonucleic acid from sources enriched in ribonuclease.</a> Biochemistry. 18, 5294-5299 (1979).</li><li>Chomczynski, P., Sacchi, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single-step+method+of+RNA+isolation+by+acid+guanidinium+thiocyanate-phenol-chloroform+extraction.">Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction.</a> Anal Biochem. 162, 156-159 (1987).</li><li>Griffin, M., Abu-El-Haija, M., Abu-El-Haija, M., Rokhlina, T., Uc, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simplified+and+versatile+method+for+isolation+of+high-quality+RNA+from+pancreas.">Simplified and versatile method for isolation of high-quality RNA from pancreas.</a> Biotechniques. 52, 332-334 (2012).</li><li>Iyer, V. R., Eisen, M. B., Ross, D. T., Schuler, G., Moore, T., Lee, J. C., Trent, J. M., Staudt, L. M., Hudson Jr, J., Boguski, M. S., 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=The+transcriptional+program+in+the+response+of+human+fibroblasts+to+serum.">The transcriptional program in the response of human fibroblasts to serum.</a> Science. 283, 83-87 (1999).</li><li>Lenstra, J. A., Beintema, J. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+amino+acid+sequence+of+mouse+pancreatic+ribonuclease.+Extremely+rapid+evolutionary+rates+of+the+myomorph+rodent+ribonucleases.">The amino acid sequence of mouse pancreatic ribonuclease. Extremely rapid evolutionary rates of the myomorph rodent ribonucleases.</a> European journal of biochemistry FEBS. 98, 399-408 (1979).</li><li>Mullin, A. E., Soukatcheva, G., Verchere, C. B., Chantler, J. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Application+of+in+situ+ductal+perfusion+to+facilitate+isolation+of+high-quality+RNA+from+mouse+pancreas.">Application of in situ ductal perfusion to facilitate isolation of high-quality RNA from mouse pancreas.</a> Biotechniques. 40, 617-621 (2006).</li><li>Rio, D. C., Ares, M., Hannon, G. J., Nilsen, T. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> RNA A Laboratory Manual. , (2011).</li><li>Streit, S., Michalski, C. W., Erkan, M., Kleeff, J., Friess, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Northern+blot+analysis+for+detection+and+quantification+of+RNA+in+pancreatic+cancer+cells+and+tissues.">Northern blot analysis for detection and quantification of RNA in pancreatic cancer cells and tissues.</a> Nat Protoc. 4, 37-43 (2009).</li><li>Zmuda, E. J., Powell, C. A., Hai, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+method+for+murine+islet+isolation+and+subcapsular+kidney+transplantation.">A method for murine islet isolation and subcapsular kidney transplantation.</a> Journal of Visualized Experiments JoVE. , (2011).</li></ol>

The authors have nothing to disclose.

Isolar RNA a partir de tecidos que são ribonuclease rico representa um grande desafio para os experimentos de biologia molecular. Vários reagentes e kits estão disponíveis no mercado que são baseada principalmente no método fenol tiocianato de guanidina de extração de RNA. Tiocianato de guanidina desnatura a proteína e, assim, reduz a actividade da ribonuclease. No entanto, a magnitude da ribonuclease no pâncreas requer modificações adicionais para protocolos padrão de isolamento de RNA. Um protocolo é rel...

Isolamento de RNA com elevada integridade é necessária para experiências de biologia molecular de rotina, tais como transferência Northern 9, qRT-PCR 1 ou a expressão do gene de perfil 5. A maioria dos métodos contemporâneos de isolamento de ARN são baseados em modificações dos protocolos de tiocianato de guanidina 2, 3. Tiocianato de guanidina é uma grande proteína desnaturante e vai efectivamente interromper a actividade de ribonuclease sob a maioria das condições. O método popular de Chomczynski e Sacchi 3 combinada de fenol na solução de tiocianato de guanidina a lise, reduzindo o tempo de isolamento de cerca de 4 horas. Muitos reagentes de extracção de RNA comercialmente disponíveis baseiam-se no método de Chomczynski e Sacchi 3. Ribonuclease tecidos ricos, como pâncreas humano ou mouse apresenta um desafio adicional para isolar RNA. Rato pâncreas pode conter até 75 mg de ribonuclease 6 alguns dos quais será lançado during destruição do tecido pancreático resultante em autólise tecido. As modificações dos protocolos de tiocianato de guanidina foram utilizados com êxito para isolar o ARN a partir de pâncreas com alta integridade 2, 4, 7, 10. Infusão de ARN estabilização reagente em rato pâncreas isolamento facilitada do RNA com elevada integridade 4, 7, 10, no entanto, a infusão de soluções para o pâncreas exige muita destreza, pode exigir instrumentos especializados, como um microscópio de dissecação e interrompendo a arquitetura do tecido durante o procedimento pode resultar em lise celular. Perfusão tecidual com reagente estabilização RNA pode interferir com outras aplicações, incluindo o isolamento de proteínas e coloração histológica. Além disso, esta técnica não é adequada para o isolamento de RNA a partir de pâncreas humanos. Outros protocolos requerem a preparação de soluções específicas pelo pesquisador 2. Relata-se um protocolo para isolar RNA com alta integridade de rato pâncreas. The protocolo utiliza elementos de métodos publicados anteriormente e é em grande parte baseada nos protocolos de reagentes padrão fenol / guanidina à base de tiocianato de lise. Ela não requer a preparação de soluções especializados, nem requer a infusão de reagentes para o pâncreas. As etapas críticas para o isolamento do ARN de sucesso incluem uma alta fenol / à base de guanidina lise reagente à relação do tecido, remoção de tecido não digerido antes da separação de fases e a inclusão de um inibidor da ribonuclease-se à solução de ARN resultantes. Usando estas e outras modificações, que tipicamente isolar o ARN com RIN superior a 7 para ser utilizado para análise da expressão do gene de rotina.

<table border="0" cellpadding="0" cellspacing="0" width="788">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Name of Reagent/ Equipment</td>
			<td style="width:93px;">Company</td>
			<td style="width:119px;">Catalog Number</td>
			<td style="width:360px;">Comments/Description</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Power Gen 500&#160;</td>
			<td style="width:93px;">Fisher Scientific</td>
			<td style="width:119px;">14-261-03&#160;</td>
			<td>Homogenizer</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">5424R</td>
			<td style="width:93px;">Eppendorf</td>
			<td style="width:119px;"></td>
			<td>Refrigerated microcentifuge</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Trizol reagent</td>
			<td style="width:93px;">Invitrogen</td>
			<td style="width:119px;">15596018</td>
			<td>Lysis reagent</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;"></td>
			<td style="width:93px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Student Vannas spring scissors</td>
			<td style="width:93px;">Fisher</td>
			<td style="width:119px;">91500-09&#160;</td>
			<td>use to cut pancreas from attached tissues</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;"></td>
			<td style="width:93px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Surgical scissors, 6 inch</td>
			<td style="width:93px;">Fisher</td>
			<td style="width:119px;">08-951-20</td>
			<td>use to cut scin of mouse</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;"></td>
			<td style="width:93px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Blunt end forceps</td>
			<td style="width:93px;">Fisher</td>
			<td style="width:119px;">1381239</td>
			<td>use to hold pancreas while dissecting</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;"></td>
			<td style="width:93px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Isoflurane USP</td>
			<td style="width:93px;">Abbott Labs</td>
			<td style="width:119px;">4/8/5210</td>
			<td>Anesthetic</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;"></td>
			<td style="width:93px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Rnase out (40 U/&#181;l)</td>
			<td style="width:93px;">Invitrogen</td>
			<td style="width:119px;">10777-019</td>
			<td>Rnase inhbitor</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;"></td>
			<td style="width:93px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:216px;">Rnase Away</td>
			<td style="width:93px;">Ambion</td>
			<td style="width:119px;">10328-011</td>
			<td>General Rnase inactivator</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;"></td>
			<td style="width:93px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">HPLC grade water</td>
			<td style="width:93px;">Fisher</td>
			<td style="width:119px;">W5-4</td>
			<td>For washing homogenizer blades</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;"></td>
			<td style="width:93px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Molecular Biology grade water</td>
			<td style="width:93px;">Hyclone</td>
			<td style="width:119px;">SH30538.03</td>
			<td>Elution of RNA</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;"></td>
			<td style="width:93px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">miRNeasy Mini kit</td>
			<td style="width:93px;">Qiagen</td>
			<td style="width:119px;">217004</td>
			<td>Purification Kit</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;"></td>
			<td style="width:93px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">2 ml microcentrifuge tubes, certified Rnase Dnase free</td>
			<td style="width:93px;">USA Scientific Plastics</td>
			<td style="width:119px;">1620-2700</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;"></td>
			<td style="width:93px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">15 ml centrifuge tubes</td>
			<td style="width:93px;">Falcon</td>
			<td style="width:119px;">352099</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;"></td>
			<td style="width:93px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">70% ethanol</td>
			<td style="width:93px;">Fisher</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;"></td>
			<td style="width:93px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">100% ethanol</td>
			<td style="width:93px;">Fisher</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;"></td>
			<td style="width:93px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">200 ul pipet tips</td>
			<td style="width:93px;">Rainin</td>
			<td style="width:119px;">GPL200F</td>
			<td>For cleaning homogenizer blades</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;"></td>
			<td style="width:93px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Chloroform</td>
			<td style="width:93px;">Fisher</td>
			<td style="width:119px;">BP1145-1</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;"></td>
			<td style="width:93px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Nanodrop</td>
			<td style="width:93px;">Thermo</td>
			<td style="width:119px;">ND-1000</td>
			<td>Spectrophotometer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;"></td>
			<td style="width:93px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Bioanalyzer</td>
			<td style="width:93px;">Agilent</td>
			<td style="width:119px;"></td>
			<td>Capillary electrophoresis analyzer to measue RNA integrity</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;"></td>
			<td style="width:93px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">RNAlater</td>
			<td style="width:93px;">Ambion</td>
			<td style="width:119px;"></td>
			<td>RNA Stabilization Reagent&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;"></td>
			<td style="width:93px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">RNeasy&#160;spin columns&#160;</td>
			<td style="width:93px;">Qiagen</td>
			<td style="width:119px;"></td>
			<td>&#160;spin columns&#160;as a part of the miRNeasy Mini kit</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;"></td>
			<td style="width:93px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Mice</td>
			<td style="width:93px;">Chales River</td>
			<td style="width:119px;">strain C57BL/6</td>
			<td style="width:360px;">Their age ranged from 4 to 12 months.&#160;&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;"></td>
			<td style="width:93px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Mice&#160;</td>
			<td style="width:93px;">Jackson Lab</td>
			<td style="width:119px;">strain 129</td>
			<td style="width:360px;">Their age ranged from 4 to 12 months.&#160;&#160;</td>
		</tr>
	</tbody>
</table>

rna isolation from mouse pancreas: a ribonuclease-rich tissue

Isolation of high-quality RNA from ribonuclease-rich tissue such as mouse pancreas presents a challenge. As a primary function of the pancreas is to aid in digestion, mouse pancreas may contain as much a 75 mg of ribonuclease. We report modifications of standard phenol/guanidine thiocyanate lysis reagent protocols to isolate RNA from mouse pancreas. Guanidine thiocyanate is a strong protein denaturant and will effectively disrupt the activity of ribonuclease under most conditions. However, critical modifications to standard protocols are necessary to successfully isolate RNA from ribonuclease-rich tissues. Key steps include a high lysis reagent to tissue ratio, removal of undigested tissue prior to phase separation and inclusion of a ribonuclease inhibitor to the RNA solution. Using these and other modifications, we routinely isolate RNA with RNA Integrity Number (RIN) greater than 7. The isolated RNA is of suitable quality for routine gene expression analysis. Adaptation of this protocol to isolate RNA from ribonuclease rich tissues besides the pancreas should be readily achievable.

O rendimento de ARN total a partir de 1 ml de homogeneizado de lise é de 20-40 ug. OD 260/280 proporções são normalmente em torno de 2.0 e RIN são consistentemente superior a 7,0. Se o NIR é ≤ 6, o isolamento necessita de ser repetida. Ocasionalmente, um RIN que é maior do que 8,0 seja alcançado. Os dois métodos mais comumente usados ​​de eutanásia de camundongos antes da remoção do pâncreas são CO 2 asfixia ou inalação de isoflurano. Ambas as técnicas são ...

Watch this Scientific Journal Video about RNA Isolation from Mouse Pancreas: A Ribonuclease-rich Tissue at JoVE.com

RNA Isolation from Mouse Pancreas: A Ribonuclease-rich Tissue

We report a procedure to isolate RNA with high integrity from the ribonuclease rich mouse pancreas.

Isolamento de RNA Rato Pâncreas: Um tecido rico em Ribonuclease

Isolation of high-quality RNA from ribonuclease-rich tissue such as mouse pancreas presents a challenge.  As a primary function of the pancreas is to aid ...

rna-isolation-from-mouse-pancreas-a-ribonuclease-rich-tissue

Research

JoVE Journal

Biology

27.4K visualizações.  The Ohio State University. We report a procedure to isolate RNA with high integrity from the ribonuclease rich mouse pancreas.

Vídeo: RNA Isolation from Mouse Pancreas: A Ribonuclease-rich Tissue

Neuronal Nuclei Isolation from Human Postmortem Brain Tissue

Neurons in the human brain become postmitotic largely during prenatal development, and thus maintain their nuclei throughout the full lifespan. However, little is known about changes in neuronal chromatin and nuclear organization during the course of development and aging, or in chronic neuropsychiatric disease. However, to date most chromatin and DNA based assays (other than FISH) lack single cell resolution. To this end, the considerable cellular heterogeneity of brain tissue poses a significant limitation, because typically various subpopulations of neurons are intermingled with different types of glia and other non-neuronal cells. One possible solution would be to grow cell-type specific cultures, but most CNS cells, including neurons, are ex vivo sustainable, at best, for only a few weeks and thus would provide an incomplete model for epigenetic mechanisms potentially operating across the full lifespan.  Here, we provide a protocol to extract and purify nuclei from frozen (never fixed) human postmortem brain. The method involves extraction of nuclei in hypotonic lysis buffer, followed by ultracentrifugation and immunotagging with anti-NeuN antibody. Labeled neuronal nuclei are then collected separately using fluorescence-activated sorting. This method should be applicable to any brain region in a wide range of species and suitable for chromatin immunoprecipitation studies with site- and modification-specific anti-histone antibodies, and for DNA methylation and other assays. 

The cellular heterogeneity of brain tissue poses a significant limitation for the study of epigenetic markings in chromatin because most assays lack single cell resolution. Neurons typically are intermingled with glia and other non-neuronal cells. We provide a protocol to extract and collect neuronal nuclei from human brain.

Isolamento Núcleos neuronais de Tecidos Humanos Postmortem Cérebro

Neurons in the human brain become postmitotic largely during prenatal development, and thus maintain their nuclei throughout the full lifespan. However, ...

Biologia

Isolation of Primary Myofibroblasts from Mouse and Human Colon Tissue

The myofibroblast is a stromal cell of the gastrointestinal (GI) tract that has been gaining considerable attention for its critical role in many GI functions. While several myofibroblast cell lines are commercially available to study these cells in vitro, research results from a cell line exposed to experimental cell culture conditions have inherent limitations due to the overly reductionist nature of the work. Use of primary myofibroblasts offers a great advantage in terms of confirming experimental findings identified in a cell line. Isolation of primary myofibroblasts from an animal model allows for the study of myofibroblasts under conditions that more closely mimic the disease state being studied. Isolation of primary myofibroblasts from human colon tissue provides arguably the most relevant experimental data, since the cells come directly from patients with the underlying disease. We describe a well-established technique that can be utilized to isolate primary myofibroblasts from both mouse and human colon tissue. These isolated cells have been characterized to be alpha-smooth muscle actin and vimentin-positive, and desmin-negative, consistent with subepithelial intestinal myofibroblasts. Primary myofibroblast cells can be grown in cell culture and used for experimental purposes over a limited number of passages.

The myofibroblast is an influential stromal cell of the gastrointestinal tract that regulates important physiologic processes in both normal and disease states. We describe a technique that allows for the isolation of primary myofibroblasts from both mouse and human colon tissue, which can be utilized for in vitro experimentation.

Isolamento de primárias Miofibroblastos de Mouse e tecido do cólon humano

The myofibroblast is  a stromal cell of the gastrointestinal (GI) tract that has been gaining  considerable attention for its critical role in many GI ...

In Vitro Pancreas Organogenesis from Dispersed Mouse Embryonic Progenitors

The pancreas is an essential organ that regulates glucose homeostasis and secretes digestive enzymes. Research on pancreas embryogenesis has led to the development of protocols to produce pancreatic cells from stem cells 1. The whole embryonic organ can be cultured at multiple stages of development 2-4. These culture methods have been useful to test drugs and to image developmental processes. However the expansion of the organ is very limited and morphogenesis is not faithfully recapitulated since the organ flattens. 
We propose three-dimensional (3D) culture conditions that enable the efficient expansion of dissociated mouse embryonic pancreatic progenitors. By manipulating the composition of the culture medium it is possible to generate either hollow spheres, mainly composed of pancreatic progenitors expanding in their initial state, or, complex organoids which progress to more mature expanding progenitors and differentiate into endocrine, acinar and ductal cells and which spontaneously self-organize to resemble the embryonic pancreas. 
We show here that the in vitro process recapitulates many aspects of natural pancreas development. This culture system is suitable to investigate how cells cooperate to form an organ by reducing its initial complexity to few progenitors. It is a model that reproduces the 3D architecture of the pancreas and that is therefore useful to study morphogenesis, including polarization of epithelial structures and branching. It is also appropriate to assess the response to mechanical cues of the niche such as stiffness and the effects on cell&#180;s tensegrity.

In Vitro Pancreas Organogenesis from Dispersed Mouse Embryonic Progenitors

The three-dimensional culture method described in this protocol recapitulates pancreas development from dispersed embryonic mouse pancreas progenitors, including their substantial expansion, differentiation and morphogenesis into a branched organ. This method is amenable to imaging, functional interference and manipulation of the niche.

In Vitro Pâncreas Organogenesis de dispersos rato embrionárias Progenitores

The pancreas is an essential organ that regulates glucose homeostasis and secretes digestive enzymes. Research on pancreas embryogenesis has led to the ...

Protein Isolation from the Developing Embryonic Mouse Heart Valve Region

Western blot analysis is a commonly employed technique for detecting and quantifying protein levels. However, for small tissue samples, this analysis method may not be sufficiently sensitive to detect a protein of interest. To overcome these difficulties, we examined protocols for obtaining protein from adult human cardiac valves and modified these protocols for the developing early embryonic mouse counterparts. In brief, the mouse embryonic aortic valve regions, including the aortic valve and surrounding aortic wall, are collected in the minimal possible volume of a Tris-based lysis buffer with protease inhibitors. If required based on the breeding strategy, embryos are genotyped prior to pooling four embryonic aortic valve regions for homogenization. After homogenization, an SDS-based sample buffer is used to denature the sample for running on an SDS-PAGE gel and subsequent western blot analysis. Although the protein concentration remains too low to quantify using spectrophotometric protein quantification assays and have sample remaining for subsequent analyses, this technique can be used to successfully detect and semi-quantify phosphorylated proteins via western blot from pooled samples of four embryonic day 13.5 mouse aortic valve regions, each of which yields approximately 1 &#956;g of protein. This technique will be of benefit for studying cell signaling pathway activation and protein expression levels during early embryonic mouse valve development.

The analysis of protein expression in young embryonic mouse valves has been hampered by the limited tissue available. This manuscript provides a protocol for preparing protein from developing embryonic mouse valve regions for western blot analysis.

Isolamento de proteínas a partir da Embryonic Rato Coração Região Válvula Desenvolvimento

Western blot analysis is a commonly employed technique for detecting and quantifying protein levels. However, for small tissue samples, this analysis ...

Isolation and Functional Analysis of Mitochondria from Cultured Cells and Mouse Tissue

Comparison between two or more distinct groups, such as healthy vs. disease, is necessary to determine cellular status. Mitochondria are at the nexus of cell heath due to their role in both cell metabolism and energy production as well as control of apoptosis. Therefore, direct evaluation of isolated mitochondria and mitochondrial perturbation offers the ability to determine if organelle-specific (dys)function is occurring. The methods described in this protocol include isolation of intact, functional mitochondria from HEK cultured cells and mouse liver and spinal cord, but can be easily adapted for use with other cultured cells or animal tissues. Mitochondrial function assessed by TMRE and the use of common mitochondrial uncouplers and inhibitors in conjunction with a fluorescent plate reader allow this protocol not only to be versatile and accessible to most research laboratories, but also offers high throughput.

Comparison of mitochondrial membrane potential between samples yields valuable information about cellular status. Detailed steps for isolating mitochondria and assessing response to inhibitors and uncouplers using fluorescence are described. The method and utility of this protocol are illustrated by use of a cell culture and animal model of cellular stress.

Isolamento e Análise Funcional de mitocôndrias de células cultivadas e mouse Tissue

Comparison between two or more distinct groups, such as healthy vs. disease, is necessary to determine cellular status. Mitochondria are at the nexus of ...

Isolation and Culture of Primary Mouse Keratinocytes from Neonatal and Adult Mouse Skin

The keratinocyte (KC) is the predominant cell type in the epidermis, the outermost layer of the skin. Epidermal KCs play a critical role in providing skin defense by forming an intact skin barrier against environmental insults, such as UVB irradiation or pathogens, and also by initiating an inflammatory response upon those insults. Here we describe methods to isolate KCs from neonatal mouse skin and from adult mouse tail skin. We also describe culturing conditions using defined growth supplements (dGS) in comparison to chelexed fetal bovine serum (cFBS). Functionally, we show that both neonatal and adult KCs are highly responsive to high calcium-induced terminal differentiation, tight junction formation and stratification. Additionally, cultured adult KCs are susceptible to UVB-triggered cell death and can release large amounts of TNF upon UVB irradiation. Together, the methods described here will be useful to researchers for the setup of in vitro models to study epidermal biology in the neonatal mouse and/or the adult mouse.

Epidermal keratinocytes form a functional skin barrier and are positioned at the front line of host defense against external environmental insults. Here we describe methods for isolation and primary culture of epidermal keratinocytes from neonatal and adult mouse skin, and induction of terminal differentiation and UVB-triggered inflammatory response from keratinocytes.

Isolamento e Cultura de Queratinócitos de Rato Primário de Pele de Rato Neonatal e Adulto

The keratinocyte (KC) is the predominant cell type in the epidermis, the outermost layer of the skin. Epidermal KCs play a critical role in providing skin ...

Nuclei Isolation from Whole Tissue using a Detergent and Enzyme-Free Method

High-throughput transcriptome and epigenome profiling requires preparation of a single cell or single nuclei suspension. Preparation of the suspension with&#160;intact cell or nuclei involves dissociation and permeabilization, steps that can introduce unwanted noise and undesirable damage. Particularly, certain cell-types such as neurons are challenging to dissociate into individual cells. Additionally, permeabilization of the cellular membrane to release nuclei requires optimization by trial-and-error, which can be time consuming, labor intensive and financially nonviable. To enhance the robustness and reproducibility of sample preparation for high-throughput sequencing, we describe a rapid enzyme and detergent-free column-based nuclei isolation method. The protocol enables efficient isolation of nuclei from the entire zebrafish brain within 20 minutes. The isolated nuclei display intact nuclear morphology and low propensity to aggregate. Further, flow cytometry allows nuclei enrichment and clearance of cellular debris for downstream application. The protocol, which should work on soft tissues and cultured cells, provides a simple and accessible method for sample preparation that can be utilized for high-throughput profiling, simplifying the steps required for successful single-nuclei RNA-seq and ATAC-seq experiments.

Single nuclei isolation relies on dissociation and detergent-based permeabilization of the cell membrane, steps that need optimization and are prone to introducing technical artifacts. We demonstrate a detergent and enzyme-free protocol for rapid isolation of intact nuclei directly from whole tissue, yielding nuclei suitable for single-nucleus RNA-seq (snRNA-Seq) or ATAC-seq.

Isolamento de núcleos de tecido inteiro usando um método detergente e sem enzimas

High-throughput transcriptome and epigenome profiling requires preparation of a single cell or single nuclei suspension. Preparation of the suspension ...

Nuclei Isolation from Adult Mouse Kidney for Single-Nucleus RNA-Sequencing

The kidneys regulate diverse biological processes such as water, electrolyte, and acid-base homeostasis. Physiological functions of the kidney are executed by multiple cell types arranged in a complex architecture across the corticomedullary axis of the organ. Recent advances in single-cell transcriptomics have accelerated the understanding of cell type-specific gene expression in renal physiology and disease. However, enzyme-based tissue dissociation protocols, which are frequently utilized for single-cell RNA-sequencing (scRNA-seq), require mostly fresh (non-archived) tissue, introduce transcriptional stress responses, and favor the selection of abundant cell types of the kidney cortex resulting in an underrepresentation of cells of the medulla.
Here, we present a protocol that avoids these problems. The protocol is based on nuclei isolation at 4 &#176;C from frozen kidney tissue. Nuclei are isolated from a central piece of the mouse kidney comprised of the cortex, outer medulla, and inner medulla. This reduces the overrepresentation of cortical cells typical for whole-kidney samples for the benefit of medullary cells such that data will represent the entire corticomedullary axis at sufficient abundance. The protocol is simple, rapid, and adaptable and provides a step towards the standardization of single-nuclei transcriptomics in kidney research.

Here, we present a protocol to isolate high-quality nuclei from frozen mouse kidneys that improve the representation of medullary kidney cell types and avoids the gene expression artifacts from enzymatic tissue dissociation.

Isolamento de Núcleos do Rim de Rato Adulto para Sequenciamento de RNA de Núcleo Único

The kidneys regulate diverse biological processes such as water, electrolyte, and acid-base homeostasis. Physiological functions of the kidney are ...

Plastoglobule Lipid Droplet Isolation from Plant Leaf Tissue and Cyanobacteria

Plastoglobule lipid droplets are a dynamic sub-compartment of plant chloroplasts and cyanobacteria. Found ubiquitously among photosynthetic species, they are believed to serve a central role in the adaptation and remodeling of the thylakoid membrane under rapidly changing environmental conditions. The capacity to isolate plastoglobules of high purity has greatly facilitated their study through proteomic, lipidomic, and other methodologies. With plastoglobules of high purity and yield, it is possible to investigate their lipid and protein composition, enzymatic activity, and protein topology, among other possible molecular characteristics. This article presents a rapid and effective protocol for the isolation of plastoglobules from chloroplasts of plant leaf tissue and presents methodological variations for the isolation of plastoglobules and related lipid droplet structures from maize leaves, the desiccated leaf tissue of the resurrection plant, Eragrostis nindensis, and the cyanobacterium, Synechocystis sp. PCC 6803. Isolation relies on the low density of these lipid-rich particles, which facilitates their purification by sucrose density flotation. This methodology will prove valuable in the study of plastoglobules from diverse species.

A fast and efficient protocol is presented for the isolation of plastoglobule lipid droplets associated with various photosynthetic organisms. The successful preparation of isolated plastoglobules is a crucial first step that precedes detailed molecular investigations such as proteomic and lipidomic analyses.

Isolamento de gotículas lipídicas de platoglobulos do tecido foliar da planta e cianobactérias

Plastoglobule lipid droplets are a dynamic sub-compartment of plant chloroplasts and cyanobacteria. Found ubiquitously among photosynthetic species, they ...

Cultura primária de células-tronco derivadas do tecido adiposo do epidídimo de camundongo

Isolation, In Vitro Expansion, and Characterization of Mesenchymal Stem Cells from Mouse Epididymal Adipose Tissue

Mesenchymal stem cells (MSCs) have been extensively studied as a new therapeutic approach, mainly to stop exacerbated inflammation due to their potential to modulate the immune response. The MSCs are immune-privileged cells capable of surviving in immunologically incompatible allogeneic transplant recipients based on low expression of class I major histocompatibility complex (MHC) molecules and in the use of cell-based therapy for allogeneic transplant. These cells can be isolated from several tissues, the most commonly used being the bone marrow and adipose tissues. We provide an easy protocol to isolate, culture, and characterize MSCs from epididymal adipose tissue of mice. The epididymal adipose tissue is surgically excised, physically fragmented, and digested with 0.15% collagenase type II solution. Then, primary adipose tissue-derived stem (ADSCs) cells are cultured and expanded in vitro, and the phenotypic characterization is performed by flow cytometry. We also provide the steps to differentiate the ADSCs into osteogenic, adipogenic, and chondrogenic cells, followed by functional characterization of each cell lineage. The protocol provided here can be used for in vivo and ex vivo experiments, and as an alternative, the adipose-derived stem cells can be used to generate MSCs-like immortalized cells.

Autor em destaque: Avançando nas abordagens de tratamento com células-tronco derivadas do tecido adiposo

The adipose tissue is an excellent source of mesenchymal stem cells. Here, we bring the step-by-step extraction, cultivation, and characterization of adipose tissue-derived stem cells (ADSCs) from Swiss mice epididymal adipose tissue.

Isolamento, expansão in vitro e caracterização de células-tronco mesenquimais do tecido adiposo epididimal de camundongos

Mesenchymal stem cells (MSCs) have been extensively studied as a new therapeutic approach, mainly to stop exacerbated inflammation due to their potential ...