We thank Mr. Hajime Ichijo for video recording and helpful advice concerning editing the video. We also thank the Osumi lab members for animal care. This work is supported by a Grant-in-Aid for Scientific Research on Innovative Area, Neural Diversity and Neocortical Organization, from MEXT of Japan (to N. O.). T. K. was supported by a Research Fellowship of JSPS for Young Scientists.

NOTA: Experimentos em animais foram realizados de acordo com o National Institutes of Health Guide para o Cuidado e Uso de Animais de Laboratório. O Comitê de Experimentação Animal da Faculdade de Medicina da Universidade de Tohoku aprovou os procedimentos experimentais aqui descritos. 1. Anestesia e Laparotomia <ol style="margin-left: 40px;"><li> Para a coleta de sangue, usar ratos machos específicos isentos de agentes patogénicos Sprague-Dawley. Rápido os ratos, pelo menos, 18 horas, enquanto o fornecimento de água. Use ratos reprodutores masculinos reformados em 6-8 meses de idade (550-650 g) para a recolha de sangue. </li><li> Fluxo de 2,5-4,0% de isoflurano, o que é um anestésico por inalação, numa caixa ligada a um aparelho de anestesia para introduzir anestesia em 2,0-3,5 L / min durante 10 min. Transferência de ratos na caixa para introduzir a anestesia. <ol><li> Confirmar anestesiados verificando a perda de resposta à estimulação com as patas com uma pinça. Cubra o nariz do wi ratosth uma máscara ligada a um aparelho de anestesia para anestesiar profundamente os ratos durante a recolha de sangue. A concentração e o fluxo são mantidos a 2,5-4,0% e 2,0-3,5 l / min, respectivamente. NOTA: halotano não deve ser utilizada para a anestesia por inalação porque os embriões cultivados no soro que é recolhida a partir de ratos anestesiados com esta exposição reagente um atraso no desenvolvimento embrionário em comparação com embriões cultivados em soro obtido a partir de ratos anestesiados com isoflurano 22. </li></ol></li><li> Para evitar a contaminação da pele, desinfectar a pele por vazamento de etanol a 70% para o abdómen de ratos anestesiados. Escolha-se a pele desinfectada e parede abdominal na região inferior, com um par de pinças e cortar estas camadas simultaneamente para a região do tórax, com um par de tesouras grandes para expor os órgãos internos. Reflectir o intestino fora da cavidade abdominal com um par de pinças. </li><li> Cortar a pele ea parede abdominal para os membros posteriores compar de tesouras grandes para expor ainda mais a região abdominal posterior. Reflectir a gordura extra no exterior da cavidade abdominal com um par de pinças. </li><li> Escolha-se a gordura visceral na linha média usando dois pares de pinças e dividir a gordura cuidadosamente numa direcção paralela para expor a aorta abdominal. Repetir este procedimento para dividir a gordura visceral no sentido longitudinal para identificar facilmente a bifurcação da aorta abdominal. Além disso, a aorta é pulsátil e pode ser distinguida a partir da veia cava adjacente usando esta característica. </li><li> Escolha-se a gordura em torno da aorta abdominal e a bifurcação cuidadosamente com duas pinças e separar a gordura na aorta abdominal. </li></ol> 2. Coleta de Sangue <ol style="margin-left: 40px;"><li> Cuidadosamente insira a ponta de uma agulha G 21, ligado a uma seringa de 20 ml imediatamente craniana à bifurcação da aorta, com o chanfro no sentido descendente. Segure a seringa com umalado, e puxe a seringa lentamente para coletar 15 ml de sangue de um rato macho. </li><li> Retire a agulha da seringa, e derramar o sangue em duas de 10 ml tubos de ensaio estéreis geladas (Figura 1A). Manter os tubos em gelo até à centrifugação para retardar a formação do coágulo de sangue. Reduzir o tempo de centrifugação por vários tubos de centrifugação de uma só vez. </li><li> Eutanásia rato anestesiado por toracotomia e cortando o coração ou decapitação. </li></ol> 3. Rato Soro Preparação <ol style="margin-left: 40px;"><li> Centrifuga-se o sangue recolhido durante 5 min a 1200 x g e à temperatura ambiente (RT) para separar o sangue nas camadas inferiores e superiores (Figura 1C). </li><li> Manter os tubos a 4 ° C durante 1,5-2 horas para corrigir o coágulo de fibrina. </li><li> Escolha-se o coágulo de fibrina na camada superior usando um par de pinças curvas, e espremer o coágulo de fibrina para separar o soro. Em seguida, pressione o coágulo de fibrina com as pinças curvas enfrentam tarefaswnwards perto da interface entre as duas camadas (Figura 1D). </li><li> Repetir o passo 3.3 para separar ainda mais o coágulo de fibrina. </li><li> Centrifugar os tubos de ensaio durante 5 min a 1200 xg e RT (Figura 1E). </li><li> Transferir cuidadosamente o soro para um tubo de 15 ml estéril, usando uma pipeta estéril numa câmara de fluxo de ar laminar. </li><li> Centrifuga-se o soro de rato recolhidos durante 5 min a 1200 xg e RT a remover todos os restantes glóbulos vermelhos. </li><li> Piscina do soro cuidadosamente em um novo 15 ml esterilizados tubo com uma pipeta estéril para evitar a contaminação por células vermelhas residuais na parte inferior do tubo (Figura 1F). </li><li> Incubar o soro em um banho de água a 56 ° C durante 30 minutos, para inactivar o sistema do complemento. </li><li> Arrefecer os tubos de soro de rato para RT no gabinete laminar do fluxo de ar. O soro deve ser aliquotado a 10 ml em tubos estéreis individuais. Armazenar os tubos a -20 ° C até à sua utilização (Figura 1H). </li></ol>

<ol>
	<li>New, D. A. T., Copp, A. J., Cockroft, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Introduction.">Introduction.</a> Mammalian Postimplantation Embryos. A Practical Approach. , 1-14 (1990).</li><li>Eto, K., Takakubo, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improved+development+of+rat+embryos+in+culture+during+the+period+of+craniofacial+morphogenesis.">Improved development of rat embryos in culture during the period of craniofacial morphogenesis.</a> J Craniofac Genet Dev Biol. 5, 351-355 (1985).</li><li>Takahashi, M., Osumi, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+method+of+rodent+whole+embryo+culture+using+the+rotator-type+bottle+culture+system.">The method of rodent whole embryo culture using the rotator-type bottle culture system.</a> J Vis Exp. (42), e2170 (2010).</li><li>New, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Whole+embryo+culture,+teratogenesis,+and+the+estimation+of+teratologic+risk.">Whole embryo culture, teratogenesis, and the estimation of teratologic risk.</a> Teratology. 42, 635-642 (1990).</li><li>Matsuo, T., 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=A+mutation+in+the+Pax-6+gene+in+rat+small+eye+is+associated+with+impaired+migration+of+midbrain+crest+cells.">A mutation in the Pax-6 gene in rat small eye is associated with impaired migration of midbrain crest cells.</a> Nat Genet. 3, 299-304 (1993).</li><li>Nomura, T., Holmberg, J., Frisen, J., Osumi, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pax6-dependent+boundary+defines+alignment+of+migrating+olfactory+cortex+neurons+via+the+repulsive+activity+of+ephrin+A5.">Pax6-dependent boundary defines alignment of migrating olfactory cortex neurons via the repulsive activity of ephrin A5.</a> Development. 133, 1335-1345 (2006).</li><li>Yamamoto, 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=Nodal+antagonists+regulate+formation+of+the+anteroposterior+axis+of+the+mouse+embryo.">Nodal antagonists regulate formation of the anteroposterior axis of the mouse embryo.</a> Nature. 428, 387-392 (2004).</li><li>Inoue, T., 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=Role+of+cadherins+in+maintaining+the+compartment+boundary+between+the+cortex+and+striatum+during+development.">Role of cadherins in maintaining the compartment boundary between the cortex and striatum during development.</a> Development. 128, 561-569 (2001).</li><li>Takahashi, M., Osumi, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pax6+regulates+specification+of+ventral+neurone+subtypes+in+the+hindbrain+by+establishing+progenitor+domains.">Pax6 regulates specification of ventral neurone subtypes in the hindbrain by establishing progenitor domains.</a> Development. 129, 1327-1338 (2002).</li><li>Calegari, F., Haubensak, W., Yang, D., Huttner, W. B., Buchholz, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tissue-specific+RNA+interference+in+postimplantation+mouse+embryos+with+endoribonuclease-prepared+short+interfering+RNA.">Tissue-specific RNA interference in postimplantation mouse embryos with endoribonuclease-prepared short interfering RNA.</a> Proc Natl Acad Sci U S A. 99, 14236-14240 (2002).</li><li>Takahashi, M., Nomura, T., Osumi, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transferring+genes+into+cultured+mammalian+embryos+by+electroporation.">Transferring genes into cultured mammalian embryos by electroporation.</a> Dev Growth Differ. 50, 485-497 (2008).</li><li>Pryor, S. E., Massa, V., Savery, D., Greene, N. D., Copp, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Convergent+extension+analysis+in+mouse+whole+embryo+culture.">Convergent extension analysis in mouse whole embryo culture.</a> Methods Mol Biol. 839, 133-146 (2012).</li><li>Kikkawa, T., 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=Dmrta1+regulates+proneural+gene+expression+downstream+of+Pax6+in+the+mammalian+telencephalon.">Dmrta1 regulates proneural gene expression downstream of Pax6 in the mammalian telencephalon.</a> Genes Cells. 18, 636-649 (2013).</li><li>Tabata, H., Nakajima, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+in+utero+gene+transfer+system+to+the+developing+mouse+brain+using+electroporation:+visualization+of+neuronal+migration+in+the+developing+cortex.">Efficient in utero gene transfer system to the developing mouse brain using electroporation: visualization of neuronal migration in the developing cortex.</a> Neuroscience. 103, 865-872 (2001).</li><li>Fukuchi-Shimogori, T., Grove, E. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neocortex+patterning+by+the+secreted+signaling+molecule+FGF8.">Neocortex patterning by the secreted signaling molecule FGF8.</a> Science. 294, 1071-1074 (2001).</li><li>Saito, T., Nakatsuji, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+gene+transfer+into+the+embryonic+mouse+brain+using+in+vivo+electroporation.">Efficient gene transfer into the embryonic mouse brain using in vivo electroporation.</a> Dev Biol. 240, 237-246 (2001).</li><li>Turnbull, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrasound+backscatter+microscopy+of+mouse+embryos.">Ultrasound backscatter microscopy of mouse embryos.</a> Methods Mol Biol. 135, 235-243 (2000).</li><li>Pierfelice, T. J., Gaiano, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrasound-guided+microinjection+into+the+mouse+forebrain+in+utero+at+E9.5.">Ultrasound-guided microinjection into the mouse forebrain in utero at E9.5.</a> J Vis Exp. (45), e2047 (2010).</li><li>Quinlan, G. A., Khoo, P. L., Wong, N., Trainor, P. A., Tam, P. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+grafting+and+labeling+in+postimplantation+mouse+embryos.">Cell grafting and labeling in postimplantation mouse embryos.</a> Methods Mol Biol. 461, 47-70 (2008).</li><li>Nagy, A., Gertsenstein, M., Vinterstein, K., Behringer, R., Nagy, A., Gertsenstein, M., Vinterstein, K., Behringer, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Roller+culture+of+postimplantation+embryos.">Roller culture of postimplantation embryos.</a> Manipulating the Mouse Embryo: A Laboratory Manual. , 237-241 (2003).</li><li>Garcia, M. D., Udan, R. S., Hadjantonakis, A. K., Dickinson, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+of+rat+serum+for+culturing+mouse+embryos.">Preparation of rat serum for culturing mouse embryos.</a> Cold Spring Harb Protoc. 2011, 391-393 (2011).</li><li>Brown-Woodman, P. D., Ritchie, H. E., Korabelnikoff, A., Emmanuel, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Replacement+of+ether+with+alternate+volatile+anesthetics+for+collection+of+rat+serum+used+in+embryo+culture.">Replacement of ether with alternate volatile anesthetics for collection of rat serum used in embryo culture.</a> Toxicol In Vitro. 18, 719-724 (2004).</li><li>Gray, J., Ross, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neural+tube+closure+in+mouse+whole+embryo+culture.">Neural tube closure in mouse whole embryo culture.</a> J Vis Exp. (56), e3132 (2011).</li><li>Machado, C. 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=Reconstruction+of+phrenic+neuron+identity+in+embryonic+stem+cell-derived+motor+neurons.">Reconstruction of phrenic neuron identity in embryonic stem cell-derived motor neurons.</a> Development. 141, 784-794 (2014).</li><li>Glanville-Jones, H. C., Woo, N., Arkell, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Successful+whole+embryo+culture+with+commercially+available+reagents.">Successful whole embryo culture with commercially available reagents.</a> Int J Dev Biol. 57, 61-67 (2013).</li><li>Ornoy, A., Yacobi, S., Yaffee, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+simple+method+of+culture+of+11.5-day-old+rat+embryos+in+DMEM/F12+and+20%+fetal+bovine+serum.">A simple method of culture of 11.5-day-old rat embryos in DMEM/F12 and 20% fetal bovine serum.</a> J Anat. 203, 419-423 (2003).</li><li>Moore-Scott, B. A., Gordon, J., Blackburn, C. C., Condie, B. G., Manley, N. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=New+serum-free+in+vitro+culture+technique+for+midgestation+mouse+embryos.">New serum-free in vitro culture technique for midgestation mouse embryos.</a> Genesis. 35, 164-168 (2003).</li><li>Kalaskar, V. K., Lauderdale, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mouse+Embryonic+Development+in+a+Serum-free+Whole+Embryo+Culture+System.">Mouse Embryonic Development in a Serum-free Whole Embryo Culture System.</a> J Vis Exp. (85), e50308 (2014).</li></ol>

No conflicts of interest are declared.

Resultados reprodutíveis em experiências CME são dependentes da utilização de alta qualidade IC de soro de rato e precisas técnica de dissecção embrião 3. Não encurte o período de jejum antes de coletar o sangue, porque o jejum é necessário padronizar as concentrações de glicose no sangue. Os ratos fêmea não deve ser utilizado para a preparação do soro, porque os níveis de hormona de alterar em animais do sexo feminino de acordo com o ciclo estral, e tais variações de hormonas estradiol ...

Uma variedade de modelos animais são utilizados na biologia do desenvolvimento para investigar os mecanismos de desenvolvimento aos níveis celular e molecular. Por exemplo, as espécies de anfíbios e de aves foram amplamente utilizados como animais modelo clássicas que são adequados para a manipulação directa de embriões porque estes embriões se desenvolvem fora da mãe. Em contraste a estes animais, embriões de mamíferos crescem no útero da mãe, e em fases posteriores do crescimento é crucialmente dependente da função do útero. Portanto, é normalmente difícil de manipular diretamente embriões de mamíferos, como os do rato e rato em estágios iniciais. Na década de 1960, Denis New estabeleceu um conjunto de mamíferos cultura de embriões (WEC) técnica usando aparatos WEC com um suprimento contínuo de oxigênio e controle de calor 1. Em WEC, ratinhos e ratos de embriões podem crescer ex vivo (isto é, fora do útero). Embora a técnica WEC foi muitas vezes utilizado em teratologia, adicionando vários isquêmicaai os compostos no meio de cultura, esta técnica também tem sido utilizado em vários estudos de biologia de desenvolvimento para examinar os mecanismos de desenvolvimento únicos em mamíferos 2-4. Por exemplo, o CME é combinado com outras técnicas, tais como a marcação celular, no tipo selvagem e mutantes embriões utilizando corante fluorescente 5, 6, o transplante de células, e introdução de genes através de lipofecção e 7 electroporação 8-13. Recentemente, na manipulação útero foi usado para analisar os processos de desenvolvimento em embriões de roedores em fases posteriores e foi combinado com as técnicas de electroporação 14-16. No entanto, estas técnicas não são adequadas para a manipulação de pós-implantação e midgestation embriões, devido à dificuldade em atingir o local de injecção exacta da solução de ADN em embriões nas fases iniciais. Embora o transplante de células guiadas por ultra-som e injeção de vetores virais em embriões (ie, Têm sido relatados E8.5-E-9.5 no mouse) no útero previamente 17,18, excelentes habilidades são necessários para realizar esses experimentos com uma elevada taxa de sucesso. Portanto, o CME com elevada acessibilidade ex vivo tem vantagens no que diz respeito à manipulação de embriões de ratinho e de rato. Centrifugadas imediatamente (IC) soro de rato preparada a partir de ratos machos é usado frequentemente para o meio WEC. Quando os embriões são cultivados na fase de pós-implantação (ou seja, mais cedo do que E8.0 no rato ou no rato E10.0), uma mistura de meio sintético e IC de soro de rato é frequentemente utilizado como um meio para WEC 19. No entanto, a cultura de embriões em meados de gestação (ou seja., E8.0-12.5 em embriões de camundongos ou E10.0-E14.5 em embriões de ratos), com 100% de soro deve ser usado como um meio, porque nenhuma mídia alternativa disponível atualmente permite embriões para crescer normalmente in vitro durante mais de 2 dias. A preparação do soro de rato de alta qualidade éum passo fundamental para alcançar reprodutibilidade nos experimentos do CME. Comparado a centrifugação retardada, IC tem a vantagem de reduzir a hemólise, quando o soro é recolhido por aperto do coágulo de fibrina, porque a maior parte dos glóbulos vermelhos já têm sido separado do coágulo de fibrina. Como soro de rato hemolítico não suporta o crescimento normal de embriões de rato e de ratinho, a preparação do soro usando centrifugação imediata é preferível para a preparação usando centrifugação retardada. Nosso protocolo contém dois passos adicionais, em comparação com outros protocolos de 18-20 (ou seja., Armazenar o sangue recolhido em gelo antes da primeira centrifugação e mantendo as amostras de sangue recolhidas durante 2 horas a 4 ° C após a primeira centrifugação). A etapa anterior pode atrasar a formação do coágulo de sangue, e o último passo promove a solidificação do coágulo de fibrina para fácil espremer. Por isso, o nosso protocolo pode ser utilizado por principiantes. No entanto, a coleta de sangue e soro reproduzindoextração de precisão, simplesmente referindo-se a livros de protocolo é extremamente difícil 19-21. Neste artigo de vídeo, demonstramos nosso protocolo padrão para a preparação de IC óptima de soro de rato, que inclui a recolha de sangue a partir da aorta abdominal de ratos machos e de extracção do soro por centrifugação.

<table border="0" cellpadding="0" cellspacing="0" width="892">
	<tbody>
		<tr height="43">
			<td height="43" style="height:43px;width:216px;">Name of Material/ Equipment</td>
			<td style="width:156px;">Company</td>
			<td style="width:119px;">Catalog Number</td>
			<td style="width:401px;">Comments/Description</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:216px;">Isoflurane</td>
			<td>Abbott</td>
			<td>B506</td>
			<td>For anesthesia of rats.</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:216px;">Large scissors</td>
			<td>Napox</td>
			<td>B-7H</td>
			<td>Stelized scissors for cutting the skin and muscle of rats.&#160;</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Curved forceps</td>
			<td>Napox</td>
			<td>A-3-2</td>
			<td>Stelized forceps for picking up the skin of rats and squeezing the fibrin clot.</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Sprague-Dawley (SD) rat</td>
			<td>Charles Rivers Laboratories</td>
			<td></td>
			<td>Retired male rats from colony in the lab or purchased retired male rats.</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Syringe (20 ml)</td>
			<td>TERUMO</td>
			<td>SS-29ESZ</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Needle (21G x 5/8&#34;)</td>
			<td>TERUMO</td>
			<td>NN-2116R</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Sterile test (spitz) tube (10 ml)</td>
			<td>ASIAKIZAI</td>
			<td style="width:119px;">1101C000B-10</td>
			<td>For collection of boold</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Sterile disposable pipette</td>
			<td>Eiken Chemical</td>
			<td>CD2000 No.4</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Sterilie disposable tube (15 ml)&#160;</td>
			<td>Falcon</td>
			<td>2196</td>
			<td></td>
		</tr>
	</tbody>
</table>

preparation of rat serum suitable for mammalian whole embryo culture

Mammalian whole embryo culture (WEC) is a widely used technique for examining pharmacological toxicity in developing mouse and rat embryos and for investigating the mechanisms of developmental processes. Immediately centrifuged (IC) rat serum is commonly used for WEC and is essential for the growth and development of cultured mouse and rat embryos ex vivo. For the culture of midgestation embryos (i.e., E8.0-12.5 for the mouse, and E10.0-14.5 for the rat), 100% rat serum is the best media for supporting the growth of the embryo ex vivo. To prepare rat serum suitable for WEC, the collected blood should be centrifuged immediately to separate the blood cells from the plasma fraction. After centrifugation, the fibrin clot forms in the upper layer; this clot should be squeezed gently using a pair of sterile forceps and subsequently centrifuged to completely separate the blood cells from the serum. In this video article, we demonstrate our standard protocol for the preparation of optimal IC rat serum, including blood collection from the abdominal aorta of male rats and extraction of the serum by centrifugation.

A Figura 1 mostra os resultados representativos dos procedimentos descritos para a separação das células do sangue e do soro. Nós normalmente obter 15 ml de sangue a partir de um rato macho reformado (Figura 1A). Por centrifugação, o sangue recolhido pode ser separada numa camada superior que contém o soro e o coágulo de fibrina, o qual é indicado com uma seta, e uma camada inferior contendo células de sangue (Figura 1C). Importante, as amostras de sangue não...

Watch this Scientific Journal Video about Preparation of Rat Serum Suitable for Mammalian Whole Embryo Culture at JoVE.com

Preparation of Rat Serum Suitable for Mammalian Whole Embryo Culture

Mammalian whole embryo culture (WEC) is widely used in teratology and developmental biology. Immediately centrifuged rat serum is commonly provided as a medium for both mouse and rat WEC. In this video, we demonstrate our standard protocol for the preparation of high-quality rat serum suitable for mammalian WEC.

Preparação de Rat Serum Indicado para cultura de embriões de mamíferos Whole

Mammalian whole embryo culture (WEC) is a widely used technique for examining pharmacological toxicity in developing mouse and rat embryos and for ...

preparation-of-rat-serum-suitable-for-mammalian-whole-embryo-culture

Research

JoVE Journal

Biology

13.8K visualizações.  Jichi Medical University. Mammalian whole embryo culture (WEC) is widely used in teratology and developmental biology. Immediately centrifuged rat serum is commonly provided as a medium for both mouse and rat WEC. In this video, we demonstrate our standard protocol for the preparation of high-quality rat serum suitable for mammalian WEC.

Vídeo: Preparation of Rat Serum Suitable for Mammalian Whole Embryo Culture

Organotypic Slice Culture of E18 Rat Brains

Organotypic slice cultures from embryonic rodent brains are widely used to study brain development. While there are often advantages to an in-vivo system, organotypic slice cultures allow one to perform a number of manipulations that are not presently feasible in-vivo. To date, organtotypic embryonic brain slice cultures have been used to follow individual cells using time-lapse microscopy, manipulate the expression of genes in the ganglionic emanances (a region that is hard to target by in-utero electroporation), as well as for pharmacological studies. In this video protocol we demonstrate how to make organotypic slice cultures from rat embryonic day 18 embryos. The protocol involves dissecting the embryos, embedding them on ice in low melt agarose, slicing the embedded brains on the vibratome, and finally plating the slices onto filters in culture dishes. This protocol is also applicable in its present form to making organotypic slice cultures from different embryonic ages for both rats and mice. 

Cultura Slice organotípicas de E18 cérebros de ratos

Organotypic slice cultures from embryonic rodent brains are widely used to study brain development. While there are often advantages to an in-vivo system, ...

Biologia

Primary Culture of Adult Rat Heart Myocytes

Cultured primary adult rodent heart cells are an important model system for cardiovascular research. Nevertheless, establishment of robust, viable cultured adult myocytes can be a technically challenging, rate-limiting step for many researchers. Here we described a protocol to obtain a high yield of adult rat heart myocytes that remain viable in culture for several days. The heart is isolated and perfused with collagenase and protease under low Ca2+ conditions to recover single myocytes. Ca2+-tolerant cells are obtained by stepwise increases in extracellular Ca2+ concentration in three subsequent wash steps. Cells are filtered, resuspended in culture medium, and plated on laminin coated slips. Cultured myocytes obtained using this protocol are viable for up to four days and are suitable for most experiments including electrophysiology, biochemistry, imaging and molecular biology.

In this paper, we described a typical way to isolate and culture adult rat heart myocytes. Collagenase and protease are used to digest and isolate single myocytes. Myocytes cultured follow this protocol meet most experiment requirements.

Cultura primária de Miócitos Coração Adulto Rat

Cultured primary adult rodent heart cells are an important model system for cardiovascular research.  Nevertheless, establishment of robust, viable ...

Preparation and Culture of Rat Lens Epithelial Explants for Studying Terminal Differentiation

The anterior surface of the ocular lens is covered by a monolayer of epithelial cells, which proliferate in an annular zone underlying the ciliary body.  Following division, these cells migrate posteriorly, where FGF diffusing from the retina induces them to differentiate into a posterior array of elongated lens fiber cells, which compose the bulk of the lens.  Differentiation of lens epithelial cells into lens fibers can be induced in vitro by culturing explants of the central region of the anterior epithelium in the presence of FGF-2.  Explants are prepared from lenses of neonatal rats by removing the lens from the eye and grasping the lens capsule on the posterior side with dissecting tweezers.  The posterior capsule is then gently torn open and pressed down into the plastic bottom of a tissue culture dish. The peripheral regions of the explant are removed with a scalpel and the central area is then cultured in the presence of 100ng/ml FGF-2 for as long as 2-3 weeks, depending on the parameters to be studied.  Since epithelial cells in cultured explants differentiate in approximate synchrony over a period of days to weeks, the time course of signaling and gene expression can be determined using molecular, biochemical, and pharmacological techniques.  Immunofluorescence microscopy is a powerful adjunct to these methods as it demonstrates the subcellular localization of proteins of interest and can reveal the physiological consequences of experimental manipulations of signaling pathways.

Explants of the central region of rat lens epithelia differentiate synchronously when cultured in the presence of FGF-2. Immunofluorescence microscopy of such cultures can provides novel information about gene expression and signaling events associated with terminal differentiation.

Preparação e Cultura de explantes Rat Lens epitelial para estudar a diferenciação terminal

The anterior surface of the ocular lens is covered by a monolayer of epithelial cells, which proliferate in an annular zone underlying the ciliary body.  ...

An ex-ovo Chicken Embryo Culture System Suitable for Imaging and Microsurgery Applications

Understanding the relationships between genetic and microenvironmental factors that drive normal and malformed embryonic development is fundamental for discovering new therapeutic strategies. Advancements in imaging technology have enabled quantitative investigation of the organization and maturing of the body plan, but later stage embryonic morphogenesis is less clear. Chicken embryos are an attractive vertebrate animal model system for this application because of its ease of culture and surgical manipulation. Early embryos can be cultured for a short time on filter paper rings, which enables complete optical access for cell patterning and fate studies1,2. Studying advanced developmental processes such as cardiac morphogenesis are traditionally performed through a window of the eggshell3-5, but this technique limits optical access due to window size. We previously developed a simple method to culture whole embryos ex-ovo on hexagonal weigh boats for up to 10 days, which enabled high resolution imaging via ultrasonography6,7. These cultures were difficult to transport, limiting the types of imaging tools available for live experiments. We here present an improved shell-less culture system with a cost-effective, portable environmental chamber. Eggs were cracked onto a hammock created by a polyurethane membrane (cling wrap) affixed circumferentially to a plastic cup partially filled with sterile water. The dimensions of the circumference and depth of the hammock were both critical to maintain surface tension, while the mechanics of the hammock and water beneath helped dampen vibrations induced by transportation. A small footprint circulating water bath was also developed to enable continuous temperature control during experimentation. We demonstrate the ability to culture embryos in this way for at least 14 days without morphogenic defect or delay and employ this system in several microsurgical and imaging applications.

An ex-ovo Chicken Embryo Culture System Suitable for Imaging and Microsurgery Applications

In this article, we present a simple methodology to enable long-term ex-ovo avian embryo culture. This technique is ideal for longitudinal experimentation requiring complete optical accessibility and/or sterile transportation in avian embryos.

Um Ex-ovo Sistema de Cultura de embriões de frango Indicado para aplicações de imagem e Microcirurgia

Understanding the relationships between genetic and microenvironmental factors that drive normal and malformed embryonic development is fundamental for ...

The Method of Rodent Whole Embryo Culture using the Rotator-type Bottle Culture System

Whole embryo culture (WEC) technique has been developed in 1950's by New and his colleagues, and applied for developmental biology 1. Although development and growth of mammalian embryos are critically dependent on the function of the placenta, WEC technique allows us to culture mouse and rat embryos ex vivo condition during limited periods corresponding to midgestation stages during embryonic day (E) 6.5-E12.5 in the mouse or E8.5-E14.5 in the rat 2, 3, 4. In WEC, we can directly target desired areas of embryos using fine glass capillaries because embryos can be manipulated under the microscope. Therefore, rodent WEC is very useful technique when we want to study dynamic developmental processes of postimplanted mammalian embryos. Up to date, several types of WEC systems have been developed 1. Among those, the rotator-type bottle culture system is most popular and suitable for long-term culture of embryos at midgestation, i.e., after E9.5 and E11.5 in the mouse and rat, respectively 1. In this video protocol, we demonstrate our standard procedures of rat WEC after E12.5 using a refined model of the original rotator system, which was designed by New and Cockroft 5, 6, and introduce various applications of WEC technique for studies in mammalian developmental biology.

Whole embryo culture technique allows us to culture mouse and rat embryos ex vivo condition during limited periods corresponding to midgestation stages. In this video protocol, we demonstrate our standard procedures of rat whole embryo culture after E12.5 using the rotator-type bottle culture system.

O método de cultura de embriões de roedores inteiro usando o Rotator do tipo Sistema de Cultura Garrafa

Whole embryo culture (WEC) technique has been developed in 1950's by New and his colleagues, and applied for developmental biology 1. Although development ...

Preparation of Rat Tail Tendons for Biomechanical and Mechanobiological Studies

Rat tail tendons (RTTs) are a common biological model used in experimental in vitro studies in the fields of tendon physiology and tendinopathy. Working with those tissues is challenging because they are very fragile, and until now there was no rigorously detailed protocol for their isolation.
Faced with these challenges, we have developed methods and instruments to facilitate manipulation of RTTs and control tissue viability, sterility and integrity. This article describes the experimental procedures used to prepare RTTs for biomechanical and mechanobiological studies. Our work is divided into four main steps: extraction, cross-sectional area measurement, rinsing and loading into the bioreactor chamber.
At each step, all procedures, materials and manipulations are presented in detail so that they can be easily reproduced. Moreover, the specific instruments developed are presented: a manipulation plate used to segregate RTTs, an optic micrometer to position the tissue during the cross-sectional area measurement and an anchoring system to attach the RTTs onto a bioreactor.
Finally, we describe the results obtained after multiple tests to validate our methods. The viability, sterility and integrity evaluations demonstrate that our procedures are sufficiently rigorous for manipulations of fragile tissues such as rat tail tendons.

This article describes the experimental procedures used to prepare rat tail tendons for biomechanical and mechanobiological studies. Several features of the main steps in preparation are demonstrated, beginning with extraction, cross-sectional area measurement, rinsing and loading into the bioreactor chamber.

Preparação de tendões da cauda de rato de Estudos biomecânicos e Mechanobiological

Rat tail tendons (RTTs) are a common biological model used in experimental in vitro studies in the fields of tendon physiology and tendinopathy. Working ...

Scale-Up of Mammalian Cell Culture using a New Multilayered Flask

A growing number of cell-based applications require large numbers of cells. Usage of single layer T-flasks, that are adequate during small-scale expansion, may become cumbersome, laborious and time-consuming when large numbers of cells are required. To address this need, the performance of a new multi-layered cell culture vessel to facilitate easy scale up of cells from single layered T-flasks will be discussed. The flasks tested are available in 3- and 5-layer format and enable culture and complete recovery of three and five times the number of cells respectively, compared to T-175 flasks. A key feature of the BD Multi-Flask is a mix/equilibration port that allows rapid in-vessel mixing as well as uniform distribution of cells and reagents within and 
between layers of each vessel and consistently produce cells that can be cultured in an environment that is congruent to T-175 flasks.
The design of these Multi-Flasks also allows for convenient pipette access for adding reagents and cells directly into the flasks as well as efficient recovery of valuable cells and reagents and reduces risk of contamination due to pouring. For applications where pouring is preferred over pipetting, the design allows for minimal residual liquid retention so as to reduce wastage of valuable cells and reagents.

Cells play an instrumental and increasing role in research, and the discovery and development of new therapeutics. With this increasing need for greater number of cells we need more efficient and effective ways for growing and harvesting attachment dependent cells. A Multilayered flask with the right features can serve this purpose.

Scale Up de Cultura de células de mamíferos utilizando um Flask New Multicamadas

A growing number of cell-based applications require large numbers of cells. Usage of single layer T-flasks, that are adequate during small-scale ...

Preparation of Mouse Embryonic Fibroblast Cells Suitable for Culturing Human Embryonic and Induced Pluripotent Stem Cells

In general, human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs)1 can be cultured under variable conditions. However, it is not easy to establish an effective system for culturing these cells. Since the culture conditions can influence gene expression that confers pluripotency in hESCs and hiPSCs, the optimization and standardization of the culture method is crucial.
The establishment of hESC lines was first described by using MEFs as feeder cells and fetal bovine serum (FBS)-containing culture medium2. Next, FBS was replaced with knockout serum replacement (KSR) and FGF2, which enhances proliferation of hESCs3. Finally, feeder-free culture systems enable culturing cells on Matrigel-coated plates in KSR-containing conditioned medium (medium conditioned by MEFs)4. Subsequently, hESCs culture conditions have moved towards feeder-free culture in chemically defined conditions5-7. Moreover, to avoid the potential contamination by pathogens and animal proteins culture methods using xeno-free components have been established8.
To obtain improved conditions mouse feeder cells have been replaced with human cell lines (e.g. fetal muscle and skin cells9, adult skin cells10, foreskin fibroblasts11-12, amniotic mesenchymal cells13). However, the efficiency of maintaining undifferentiated hESCs using human foreskin fibroblast-derived feeder layers is not as high as that from mouse feeder cells due to the lower level of secretion of Activin A14. Obviously, there is an evident difference in growth factor production by mouse and human feeder cells.
Analyses of the transcriptomes of mouse and human feeder cells revealed significant differences between supportive and non-supportive cells. Exogenous FGF2 is crucial for maintaining self-renewal of hESCs and hiPSCs, and has been identified as a key factor regulating the expression of Tgf&beta;1, Activin A and Gremlin (a BMP antagonist) in feeder cells. Activin A has been shown to induce the expression of OCT4, SOX2, and NANOG in hESCs15-16.
For long-term culture, hESCs and hiPSCs can be grown on mitotically inactivated MEFs or under feeder-free conditions in MEF-CM (MEF-Conditioned Medium) on Matrigel-coated plates to maintain their undifferentiated state. Success of both culture conditions fully depends on the quality of the feeder cells, since they directly affect the growth of hESCs.
Here, we present an optimized method for the isolation and culture of mouse embryonic fibroblasts (MEFs), preparation of conditioned medium (CM) and enzyme-linked immunosorbent assay (ELISA) to assess the levels of Activin A within the media.

The quality of mouse embryonic fibroblasts (MEFs) is dictated by the right strain of mouse such as CF-1. Pluripotency-supportive MEFs and conditioned media (CM) obtained from these should contain optimal concentrations of Activin A, Gremlin and Tgf&beta;1 needed for the Activin/Nodal and FGF pathways to co-operatively maintain self-renewal and pluripotency.

Preparação de células embrionárias de camundongos Fibroblastos adequados para a cultura de células-tronco embrionárias humanas e pluripotentes induzidas

In general, human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs)1 can be cultured under variable conditions. However, it ...

Mouse Embryonic Development in a Serum-free Whole Embryo Culture System

Mid-gestation stage mouse embryos were cultured utilizing a serum-free culture medium prepared from commercially available stem cell media supplements in an oxygenated rolling bottle culture system. Mouse embryos at E10.5 were carefully isolated from the uterus with intact yolk sac and in a process involving precise surgical maneuver the embryos were gently exteriorized from the yolk sac while maintaining the vascular continuity of the embryo with the yolk sac. Compared to embryos prepared with intact yolk sac or with the yolk sac removed, these embryos exhibited superior survival rate and developmental progression when cultured under similar conditions. We show that these mouse embryos, when cultured in a defined medium in an atmosphere of 95% O2 / 5% CO2 in a rolling bottle culture apparatus at 37 &#176;&#8203;C for 16-40 hr, exhibit morphological growth and development comparable to the embryos developing in utero. We believe this method will be useful for investigators needing to utilize whole embryo culture to study signaling interactions important in embryonic organogenesis.

Serum utilized in embryo cultures contains unknown components that can affect the outcome of experiments especially in studies involving signaling interactions. Here we utilized a serum-free oxygenated culture system and show that mid-gestation mouse embryos cultured for 16-40 hr&#160;exhibit morphological development comparable to embryos developing in utero.

Rato Desenvolvimento Embrionário em todo um sistema de cultura de embriões sem soro

Mid-gestation stage mouse embryos were cultured utilizing a serum-free culture medium prepared from commercially available stem cell media supplements in ...

Flat Mount Preparation for Observation and Analysis of Zebrafish Embryo Specimens Stained by Whole Mount In situ Hybridization

The zebrafish embryo is now commonly used for basic and biomedical research to investigate the genetic control of developmental processes and to model congenital abnormalities. During the first day of life, the zebrafish embryo progresses through many developmental stages including fertilization, cleavage, gastrulation, segmentation, and the organogenesis of structures such as the kidney, heart, and central nervous system. The anatomy of a young zebrafish embryo presents several challenges for the visualization and analysis of the tissues involved in many of these events because the embryo develops in association with a round yolk mass. Thus, for accurate analysis and imaging of experimental phenotypes in fixed embryonic specimens between the tailbud and 20 somite stage (10 and 19 hours post fertilization (hpf), respectively), such as those stained using whole mount in situ hybridization (WISH), it is often desirable to remove the embryo from the yolk ball and to position it flat on a glass slide. However, performing a flat mount procedure can be tedious. Therefore, successful and efficient flat mount preparation is greatly facilitated through the visual demonstration of the dissection technique, and also helped by using reagents that assist in optimal tissue handling. Here, we provide our WISH protocol for one or two-color detection of gene expression in the zebrafish embryo, and demonstrate how the flat mounting procedure can be performed on this example of a stained fixed specimen. This flat mounting protocol is broadly applicable to the study of many embryonic structures that emerge during early zebrafish development, and can be implemented in conjunction with other staining methods performed on fixed embryo samples.

Flat Mount Preparation for Observation and Analysis of Zebrafish Embryo Specimens Stained by Whole Mount In situ Hybridization

The zebrafish embryo is an excellent model for developmental biology research. During embryogenesis, zebrafish develop with a yolk mass, which presents three-dimensional challenges for sample observation and analysis. This protocol describes how to create two-dimensional flat mount preparations of whole mount in situ (WISH) stained zebrafish embryo specimens.

Monte Preparação Plano de observação e análise de amostras de embriões Zebrafish manchado por inteiro Monte<em&gt; Em situ</em&gt; Hibridização

The zebrafish embryo is now commonly used for basic and biomedical research to investigate the genetic control of developmental processes and to model ...