Bu çalışma Ulusal Sağlık ve Tıp Araştırma Konseyi Avustralya (proje hibe hayır °. 6.288.480) ve Scobie ve Clare MacKinnon Güven tarafından desteklenmiştir.

1. RT Reaksiyon Micromixing <ol><li> Micromixing RT tepki gerçekleştirmeden önce, RT tepki istenilen sıcaklığa micromixer dengelenmesi. <ol><li> Micromixer 37 içine yerleştirin ° C (veya RT tedarikçi tarafından tavsiye edilen sıcaklık) inkübatör RT reaksiyonun başlangıcı için en az 1 saat önce için. </li></ol></li><li> RT karışımı ters transkriptaz tedarikçisi göre ayarlayın (örneğin Promega, Qiagen gelen Omniscript MMTV-RT) talimatları yerine ng-mg giriş toplam RNA (örneğin 0.1-1pg/μl), tek hücreli miktarda hariç tedarikçiler tarafından tavsiye edilen miktarda. <ol><li> Biz standart steril, nükleaz 200μL ince duvarlı PCR tüpleri kullanırlar. </li></ol></li><li> Karıştırma için hazır olan en kısa sürede güvenli bir şekilde micromixer içine pozisyon RT tüpler. Micromixer RT reaksiyon süresi 37 ° C inkübatör içinde kalmalıdır. </li><li> Uygun frekans ve micromixing genlik seçin. Bu örnekte, 150Hz kullanın. </li><li> Micromixer açın ve RT tepki (60 dakika) süresi boyunca bekletin. </li><li> Micromixer kapatın ve RT reaksiyon tamamlandıktan sonra RT tüpleri almak. </li><li> RT tüpleri, buz üzerinde yerleştirin ve kantitatif Polimeraz Zincir Reaksiyonu (qPCR veya gerçek-zamanlı PCR) gibi daha fazla uygulamaları ile normal olarak devam edin. </li></ol> 2. Temsilcisi Sonuçlar: RT reaksiyonlar bağlamında micromixing yararı cDNA verimi diğer karıştırma yöntemleri (örneğin, sallayarak karıştırın veya öğütme) kullanıldığında göreceli bir artış. Bu cDNA kullanarak kantitatif Polimeraz Zincir Reaksiyonu (qPCR veya gerçek-zamanlı PCR) sonraki analizi üzerine, örneğin, görülebilmektedir. Şekil 2A hemen önce RT inkübasyon (siyah, &quot;öğütme&quot; RT reaksiyon öğütme ile karşılaştırıldığında, ilk 5 dakika için micromixing etkileri (mavi, &quot;micromixed5&quot;) ya da tüm 60 dakika (kırmızı, &quot;micromixed60&quot;) göstermektedir .) Bu durumda önceki RT reaksiyon hacmi 25μL ve total RNA 2.5pg içeriyordu. cDNA temsil Nurr-1 mRNA algılamak için tasarlanmış primerler kullanılarak qPCR izleri yukarıda gösterildiği anlamına gelir ± 3 Bu aynı deneyi tekrarlar% 50 maksimum floresans ulaşmak için döngüleri sayısı SEM&#39;ler aşağıda çizilir. Yıldız işareti (Tukey çoklu karşılaştırmalar tek yönlü ANOVA) istatistiksel olarak anlamlı bir farklılık göstermektedir. Önceki RT reaksiyon tüm 60 dakika boyunca micromixing öğütme üzerinde önemli bir gelişme ise önceki RT reaksiyon ilk 5 dakika micromixing öğütme üzerinde anlamlı olmayan iyileşme üretilen, büyüklüğü yaklaşık 15 qPCR eşdeğer döngüleri, ortalama. Micromixing yararı da elde edilen sonraki qPCR ürünlerin erime eğrisi analizinin görülebilir. Sadece tutarsız qPCR üretilen ilk 5 dakika veya öğütme için micromixing ise, önceki RT reaksiyon tüm 60 dakika boyunca micromixing Şekil 2B gösterilen deney, tutarlı bir yinelenen örnekleri qPCR sinyal (Şekil 2BA, 2 kırmızı izleri) sonuçlandı izleri (Şekil 2BA, 2 mavi izleri ve 2 siyah izleri, sırasıyla). Gri izleri qPCR reaksiyon kaldı cDNA hangi negatif kontroller (&quot;negatif&quot;). Bu deneyde qPCR ürünleri belliydi sıcaklığı (yani erime eğrisi analizi) Ramping denatüre olduğunu ne zaman uygun PCR ürünleri (yani, mRNA çok daha yüksek konsantrasyonlarda ters qPCR transkripsiyonu ve amplifiye edildi, elde edilen aynıydı bir Amplikon gösterilmemiştir) 60 dakika (Şekil 2BB, 2 kırmızı izleri) micromixed olmuştu sadece RT reaksiyonlar sunuldu. Tüm diğerleri (yani micromixed5, öğütme ve negatif kontroller), alternatif Amplikon ürünler (örneğin, astar dimerleri) oluşturulur. <img src="/files/ftp_upload/3144/3144fig1.jpg" alt="Şekil 1"/> Şekil 1 standart laboratuvar RT reaksiyonlara micromixing uygulamak için protokol Akış diyagramı. Referanslar 13,14 fiziksel prensibi yer micromixer ve nasıl bir in-house micromixer inşa etmek için daha ayrıntılı açıklamalar verilmiştir <img src="/files/ftp_upload/3144/3144fig2.jpg" alt="Şekil 2"/> Şekil 2 RT aksi standart laboratuvar RT reaksiyonlarda mRNA tek hücreli miktarlarda oluşan reaksiyonlar önceki uygulanan micromixing faydaları gösteren Temsilcisi qPCR veri Nurr-1 genini kodlayan cDNA temsil eden mRNA tespit qPCR izleri Bir ​​Örnek. Önceki RT reaksiyonlar 25μL hacmi toplam RNA 2.5pg yer alan ve 37 ° C&#39;de 60 dakika için bir kuluçka yapıldı. RT reaksiyonlar R öğütme tarafından karıştırıldıT RT reaksiyon (mavi izleri &quot;micromixed5&quot;) ilk 5 dakika boyunca (kırmızı izleri &quot;micromixed60&quot; micromixed veya RT reaksiyon tüm 60 dakika boyunca micromixed inkübasyon (siyah izleri &quot;öğütme&quot;) önce karışmaktadır .) Ortalamalar ±% 50 maksimum floresans ulaşmak için gerekli qPCR döngülerinin sayısı SEM&#39;ler aşağıda çizilir n = 3 bu deneyi tekrarlar. Asterisk (Tukey çoklu karşılaştırmalar tek yönlü ANOVA) anlamlı bir farklılık gösterir. B bir başka qPCR deney 25μL hacmi toplam RNA içeren 25pg RT reaksiyonlar aşağıdaki Nurr-1 cDNA ürünü inceleyerek, bu sefer. qPCR izlerinin yanı sıra elde edilen qPCR ürün eğrisi analizi (a) erime (b) farklı karıştırma koşullar için gösterilmiştir. Hiçbir cDNA önceki RT tepki olarak dahil edildiği negatif kontrolleri de (gri izleri, &quot;negatif&quot;) yer almaktadır. MRNA çok daha yüksek konsantrasyonlarda RT reaksiyonlar da yapılan ve (b), micromixed60 için (kırmızı izlerini) örnekleri aynı erime eğrisi zirveleri (veriler gösterilmemiştir) üretildi .

<ol>
	<li>Livesey, F. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Brief+Funct+Genomic+Proteomic.">Brief Funct Genomic Proteomic.</a> 2 (1), 31-31 (2003).</li><li>Aumann, T. D., Gantois, I., Egan, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Exp Neurol. 213 (2), 419-419 (2008).</li><li>Ottino, J. M., Wiggins, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Philos Transact A Math Phys Eng Sci. 362 (1818), 923-923 (2004).</li><li>Losey, M. W., Jackman, R. J., Firebaugh, S. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> J Microelectromech. Syst. 11, 709-709 (2002).</li><li>Bontoux, N., Dauphinot, L., Vitalis, 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> Lab Chip. 8 (3), 443-443 (2008).</li><li>Marcus, J. S., Anderson, W. F., Quake, S. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Anal Chem. 78 (9), 3084-3084 (2006).</li><li>Marcus, J. S., Anderson, W. F., Quake, S. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Anal Chem. 78 (3), 956-956 (2006).</li><li>Warren, L., Bryder, D., Weissman, I. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Proc Natl Acad Sci U S A. 103 (47), 17807-17807 (2006).</li><li>Jiao, Z. J., Huang, X. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Microfluidics Nanofluidics. 6, 847-847 (2009).</li><li>Ahmed, D., Xiaole, M., Juluri, B. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Microfluidics Nanofluidics. 7, 727-727 (2009).</li><li>Paxton, W. F., O'Hara, M. J., Peper, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Anal Chem. 80, 4070-4070 (2008).</li><li>Autom, L. a. b. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> 11, 399-399 (2006).</li><li>Petkovic-Duran, K., Manasseh, R., Zhu, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> 47 (4), 827-827 (2009).</li><li>Boon, W. C., Petkovic-Duran, K., White, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> 50 (2), 116-116 (2011).</li><li>Liu, R. H., Lenigk, R., Druyor-Sanchez, R. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Anal Chem. 75 (8), 1911-1911 (1911).</li><li>Riley, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ann+Rev+Fluid+Mech.">Ann Rev Fluid Mech.</a> 33, 43-43 (2001).</li><li>Whitehill, J., Neild, A., Ng, 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> Applied Physics Letters. 96 (5), 053501-053501 (2010).</li></ol>

Yazarlar ifşa etmek için bir şey var.

Standart laboratuvar RT reaksiyonlara micromixing uygulama yöntemi, tabii ki, tutabilen burada açıklanan herhangi bir yöntemle (örneğin, hücre parçalama, lazer yakalama mikrodiseksiyon) ile hasat mRNA. Aynı zamanda herhangi bir marka veya türleri RT reaktifleri, herhangi bir sıcaklık (micromixer malzemelerin tolerans içinde), ve herhangi bir süre oluşur. Örneğin, RT rastgele hexamer veya oligo-dT primerleri oluşan reaksiyonlar gelişmiş cDNA verim gözlemledik. Aşağıdaki kısıtlamalara uygun diğe...

<table border="1"><tbody><tr><th> Reaktifin Adı </th><th> Şirket </th><th> Katalog numarası </th><th> Yorumlar (isteğe bağlı) </th></tr><tr><td> Total RNA ek bileşenini dondurulmuş akut hazırlanan yetişkin farenin orta beyin dilimleri izole edildi </td><td></td><td></td><td></td></tr><tr><td> PicoPure RNA İzolasyon Kiti </td><td> Arcturus, CA, USA </td><td> KIT0204 </td><td> Kiti artık Applied Biosystems edinilebilir. </td></tr><tr><td> DNA ücretsiz DNaz Arıtma ve Kaldırma Reaktifler </td><td> Ambion </td><td> AM1906M </td><td></td></tr><tr><td> Rastgele hexamer primerleri </td><td> Promega </td><td> C1181 </td><td></td></tr><tr><td> AMV-RT </td><td> Promega </td><td> M5101 </td><td></td></tr><tr><td> dNTP seti </td><td> Promega </td><td> U1240 </td><td></td></tr><tr><td> RNasin Ribonükleaz İnhibitörü </td><td> Promega </td><td> N2111 </td><td></td></tr><tr><td> Nükleazlar-Ücretsiz Su </td><td> Promega </td><td> P1193 </td><td></td></tr><tr><td> SYBR Yeşil PCR Master Mix </td><td> Uygulamalı Biosystem </td><td> 4309155 </td><td></td></tr><tr><td> Hprt ileri (20mer): CTT TGC TGA SKK GCT GGA TT </td><td></td><td></td><td></td></tr><tr><td> Hprt ters (20mer): TAT GTC CCC CGT TGA CTG AT </td><td></td><td></td><td></td></tr><tr><td> Nurr1 ileri (23mer): CAG CTC CGA TTT CTT AAC TTK AG </td><td></td><td></td><td></td></tr><tr><td> Nurr1 ters (23mer): GGT GAG GTC CAT GCT AAA CTT GA </td><td></td><td></td><td></td></tr><tr><td> 1000 NanoDrop Spektrofotometre. </td><td> Thermo Scientific </td><td></td><td></td></tr><tr><td> Corbett Rotor Gen RG-6000 </td><td> Corbett Yaşam Bilimleri </td><td></td><td> Corbett Yaşam Bilimleri QIAGEN tarafından Temmuz 2008&#39;de satın alındı </td></tr></tbody></table>

increasing cdna yields from single-cell quantities of mrna in standard laboratory reverse transcriptase reactions using acoustic microstreaming

Gen ekspresyonu hücre davranışı ile ilişkilendirerek ideal tek hücre düzeyinde yapılır. Ancak, tek bir hücrenin (1-5, 1-50pg toplam RNA ya da% 0.01-2.5pg mRNA, hücre başına 1) mevcut labil mRNA transkripsiyonu tersine çevirmek için önce küçük bir miktar daha çok düşürür, çünkü bu kolayca elde değil . istikrarlı bir cDNA kopyası haline. Örneğin, standart laboratuar reaktifleri ve donanım kullanarak, genlerin sadece az sayıda hücre başına 2 nitel değerlendirilir olabilir. MRNA tek hücreli miktarda oluşan standart laboratuvar ters transkriptaz (RT) reaksiyonlar (mikrolitrelik hacimleri yani standart reaktifler) verimliliği artırmak için bir şekilde düşürür önce mRNA cDNA dönüştürülebilir, böylece daha hızlı reaktifler karıştırmak olacaktır. Ancak mikrolitrelik ölçekler sıvı akışı laminer olduğunu, çünkü bu önemsiz değildir, yani mevcut karıştırma yöntemleri (sallayarak, vorteks ve öğütme yani), etkin bir şekilde reaktifleri karıştırmak için yeterli kaotik hareket üretemez. Bu sorunu çözmek için, mikro ölçekli karıştırma teknikleri 3,4 kullanılır. Mikroakışkan tabanlı karıştırma teknolojileri başarıyla RT reaksiyon verimi 5-8 artış geliştirilmiştir. Ancak, Mikroakiskan teknolojileri, nispeten pahalı ve henüz yaygın değil özel bir donanım gerektirir. Daha ucuz, daha rahat bir çözüm arzu edilir. Bu çalışmanın ana amacı, mRNA tek hücreli miktarlarda oluşan standart laboratuvar RT reaksiyonlar bir romanı &quot;micromixing&quot; tekniği uygulaması cDNA verimi önemli ölçüde artırır nasıl göstermektir. Biz cDNA verim sağlar yaklaşık 10-100-katlama, artış bulabilirsiniz: (1) daha fazla sayıda hücre başına analiz edilmesi gereken genler, gen ekspresyonu (2) daha düşük bolluk genlerin kantitatif analiz ve (3) daha iyi algılama tek hücre. Micromixing akustik, 9-12 küçük bir engel etrafında yayılan ses dalgalarını engel yakın bir ortalama akışı oluşturmak bir fenomen microstreaming dayanmaktadır. Biz kilit bir sadeleştirme ile akustik bir microstreaming tabanlı cihaz (&quot;micromixer&quot;); akustik microstreaming sistemi, küçük bir eğrilik 13 yarıçapı ile bir sıvı-hava arayüzü sağlayarak ses frekansları elde edilebilir . Bir tüp bir çözüm mikrolitrelik hacmi menisküs uygun küçük bir eğrilik yarıçapı sağlar. Ses frekanslarının kullanımı, donanım ucuz ve 13 çok yönlü olması anlamına gelir ve standart laboratuvar sonicators olabileceği gibi, nükleik asitler ve diğer biyokimyasal reaktifler zarar görmezler.

Watch this Scientific Journal Video about Increasing cDNA Yields from Single-cell Quantities of mRNA in Standard Laboratory Reverse Transcriptase Reactions using Acoustic Microstreaming at JoVE.com

Increasing cDNA Yields from Single-cell Quantities of mRNA in Standard Laboratory Reverse Transcriptase Reactions using Acoustic Microstreaming

Biz aksi takdirde standart laboratuvar ters transkripsiyon reaksiyonları mRNA tek hücreli miktarda cDNA verimi artırmak için yeni bir yöntem açıklanmaktadır. Yenilik, titreme, vorteks veya öğütme daha etkili mikrolitrelik ölçekler sıvıları karıştırmak için, akustik microstreaming fenomeni kullanan bir micromixer, kullanımı bulunur.

Akustik Microstreaming kullanarak Standart Laboratuvar Reverse Transcriptase reaksiyonlarda mRNA Tek hücreli Miktarları cDNA Verim artırılması

Correlating gene expression with cell behavior is ideally done at the single-cell level.  However, this is not easily achieved because the small amount of ...

increasing-cdna-yields-from-single-cell-quantities-mrna-standard

Research

JoVE Journal

Bioengineering

10.1K Görüntüleme.  University of Melbourne. Biz aksi takdirde standart laboratuvar ters transkripsiyon reaksiyonları mRNA tek hücreli miktarda cDNA verimi artırmak için yeni bir yöntem açıklanmaktadır. Yenilik, titreme, vorteks veya öğütme daha etkili mikrolitrelik ölçekler sıvıları karıştırmak için, akustik microstreaming fenomeni kullanan bir micromixer, kullanımı bulunur.

Video: Increasing cDNA Yields from Single-cell Quantities of mRNA in Standard Laboratory Reverse Transcriptase Reactions using Acoustic Microstreaming

High Throughput MicroRNA Profiling: Optimized Multiplex qRT-PCR at Nanoliter Scale on the Fluidigm Dynamic ArrayTM IFCs

The broad involvement of miRNAs in critical processes underlying development, tissue homoeostasis and disease has led to a surging interest among the research and pharmaceutical communities. To study miRNAs, it is essential that the quantification of microRNA levels is accurate and robust. By comparing wild-type to small RNA deficient mouse embryonic stem cells (mESC), we revealed a lack of accuracy and robustness in previous published multiplex qRT-PCR techniques. Here, we describe an optimized method, including purifying away excessive primers from previous multiplex steps before singleplex real time detection, which dramatically increases the accuracy and robustness of the technique. Furthermore, we explain how performing the technique on a microfluidic chip at nanoliter volumes significantly reduces reagent costs and permits time effective high throughput miRNA expression profiling.

Here we describe an optimized multiplex reverse transcriptase quantitative PCR (qRT-PCR) protocol in combination with a microfluidic platform as a cost and time effective high-throughput screening tool for microRNA (miRNA) expression levels, especially when working with limited amounts of sample.

Yüksek Verimli MicroRNA Profil: Optimize edilmiş, Multiplex QRT-PCR Fluidigm Dinamik ArrayTM IFCS Nanoliter Ölçeğinde

The broad involvement of miRNAs in critical processes underlying development, tissue homoeostasis and disease has led to a surging interest among the ...

Biyomühendislik

Adapting 3' Rapid Amplification of CDNA Ends to Map Transcripts in Cancer

Maturation of eukaryotic mRNAs involves 3&#39; end formation, which involves the addition of a poly(A) tail. In order to map the 3&#39; end of a gene, the traditional method of choice is 3&#39; rapid amplification of cDNA ends (3&#39; RACE). Protocols for 3&#39; RACE require the careful design and selection of nested primers within the 3&#39; untranslated region (3&#39; UTR) of the target gene of interest. However, with a few modifications the protocol can be used to include the entire 3&#39; UTR and sequences within the open reading frame (ORF), providing a more comprehensive picture of the relationship between the ORF and the 3&#39; UTR. This is in addition to identification of the polyadenylation signal (PAS), as well as the cleavage and polyadenylation site provided by conventional 3&#39; RACE. Expanded 3&#39; RACE can detect unusual 3&#39; UTRs, including gene fusions within the 3&#39; UTR, and the sequence information can be used to predict potential miRNA binding sites as well as AU rich destabilizing elements that may affect the stability of the transcript.

The two different 3&#39; rapid amplification of cDNA ends (3&#39; RACE) protocols described here make use of two different DNA polymerases to map sequences that include a segment of the open reading frame (ORF), the stop codon, and the entire 3&#39; UTR of a transcript using RNA obtained from different cancer cell lines.

3' adapte CDNA hızlı amplifikasyon transkript kanser eşlemek için sona erer

Maturation of eukaryotic mRNAs involves 3&#39; end formation, which involves the addition of a poly(A) tail. In order to map the 3&#39; end of a gene, the ...

Genetik

Transcriptome Analysis of Single Cells

Many gene expression analysis techniques rely on material isolated from heterogeneous populations of cells from tissue homogenates or cells in culture.1,2,3 In the case of the brain, regions such as the hippocampus contain a complex arrangement of different cell types, each with distinct mRNA profiles. The ability to harvest single cells allows for a more in depth investigation into the molecular differences between and within cell populations. We describe a simple and rapid method for harvesting cells for further processing. Pipettes often used in electrophysiology are utilized to isolate (using aspiration) a cell of interest and conveniently deposit it into an Eppendorf tube for further processing with any number of molecular biology techniques. Our protocol can be modified for the harvest of dendrites from cell culture or even individual cells from acute slices.
We also describe the aRNA amplification method as a major downstream application of single cell isolations. This method was developed previously by our lab as an alternative to other gene expression analysis techniques such as reverse-transcription or real-time polymerase chain reaction (PCR).4,5,6,7,8 This technique provides for linear amplification of the polyadenylated RNA beginning with only femtograms of material and resulting in microgram amounts of antisense RNA. The linearly amplified material provides a more accurate estimation than PCR exponential amplification of the relative abundance of components of the transcriptome of the isolated cell. The basic procedure consists of two rounds of amplification. Briefly, a T7 RNA polymerase promoter site is incorporated into double stranded cDNA created from the mRNA transcripts. An overnight in vitro transcription (IVT) reaction is then performed in which T7 RNA polymerase produces many antisense transcripts from the double stranded cDNA. The second round repeats this process but with some technical differences since the starting material is antisense RNA. It is standard to repeat the second round, resulting in three rounds of amplification. Often, the third round in vitro transcription reaction is performed using biotinylated nucleoside triphosphates so that the antisense RNA produced can be hybridized and detected on a microarray.7,8

In this article we describe a simple method for the harvesting of single cells from rat primary neuronal cultures and subsequent transcriptome analysis using aRNA amplification. This approach is generalizable to any cell type.

Tek Hücre Transcriptome Analizi

Many gene expression analysis techniques rely on material isolated from heterogeneous populations of cells from tissue homogenates or cells in ...

Nörobilim

Transcription Start Site Mapping Using Super-low Input Carrier-CAGE

Cap analysis of gene expression (CAGE) is a method used for single-nucleotide resolution detection of RNA polymerase II transcription start sites (TSSs). Accurate detection of TSSs enhances identification and discovery of core promoters. In addition, active enhancers can be detected through signatures of bidirectional transcription initiation. Described here is a protocol for performing super-low input carrier-CAGE (SLIC-CAGE). This SLIC adaptation of the CAGE protocol minimizes RNA losses by artificially increasing the RNA amount through use of an in vitro transcribed RNA carrier mix that is added to the sample of interest, thus enabling library preparation from nanogram-amounts of total RNA (i.e., thousands of cells). The carrier mimics the expected DNA library fragment length distribution, thereby eliminating biases that could be caused by the abundance of a homogenous carrier. In the last stages of the protocol, the carrier is removed through degradation with homing endonucleases and the target library is amplified. The target sample library is protected from degradation, as the homing endonuclease recognition sites are long (between 18 and 27 bp), making the probability of their existence in the eukaryotic genomes very low. The end result is a DNA library ready for next-generation sequencing. All steps in the protocol, up to sequencing, can be completed within 6 days. The carrier preparation requires a full working day; however, it can be prepared in large quantities and kept frozen at -80 &#176;C. Once sequenced, the reads can be processed to obtain genome-wide single-nucleotide resolution TSSs. TSSs can be used for core promoter or enhancer discovery, providing insight into gene regulation. Once aggregated to promoters, the data can also be used for 5&#8217;-centric expression profiling.

Cap Analysis of Gene Expression (CAGE) is a method for genome-wide quantitative mapping of mRNA 5&#8217;ends to capture RNA polymerase II transcription start sites at a single-nucleotide resolution. This work describes a low-input (SLIC-CAGE) protocol for generation of high-quality libraries using nanogram-amounts of total RNA.

Transkripsiyon başlangıç site haritalama süper düşük giriş taşıyıcı-kafes kullanarak

Cap analysis of gene expression (CAGE) is a method used for single-nucleotide resolution detection of RNA polymerase II transcription start sites (TSSs). ...

Analyzing Gene Expression from Marine Microbial Communities using Environmental Transcriptomics

Analogous to metagenomics, environmental transcriptomics (metatranscriptomics) retrieves and sequences environmental mRNAs from a microbial assemblage without prior knowledge of what genes the community might be expressing. Thus it provides the most unbiased perspective on community gene expression in situ. Environmental transcriptomics protocols are technically difficult since prokaryotic mRNAs generally lack the poly(A) tails that make isolation of eukaryotic messages relatively straightforward 1 and because of the relatively short half lives of mRNAs 2. In addition, mRNAs are much less abundant than rRNAs in total RNA extracts, thus an rRNA background often overwhelms mRNA signals. However, techniques for overcoming some of these difficulties have recently been developed. A procedure for analyzing environmental transcriptomes by creating clone libraries using random primers to reverse-transcribe and amplify environmental mRNAs was recently described was successful in two different natural environments, but results were biased by selection of the random primers used to initiate cDNA synthesis 3. Advances in linear amplification of mRNA obviate the need for random primers in the amplification step and make it possible to use less starting material decreasing the collection and processing time of samples and thereby minimizing RNA degradation 4. In vitro transcription methods for amplifying mRNA involve polyadenylating the mRNA and incorporating a T7 promoter onto the 3 end of the transcript. Amplified RNA (aRNA) can then be converted to double stranded cDNA using random hexamers and directly sequenced by pyrosequencing 5. A first use of this method at Station ALOHA demonstrated its utility for characterizing microbial community gene expression 6.

We present a method for generating cDNA from environmental mRNA. In general, total RNA is first collected from the environment, rRNA is selectively removed, mRNA is selectively amplified, and cDNA synthesized from the enriched mRNA pool is sequenced. Recovered sequences can be annotated using standard bioinformatics techniques to identify the expressed genes.

Çevre transkriptomik kullanarak Deniz Mikrobiyal Toplulukları Gen İfade Analizi

Analogous to metagenomics, environmental transcriptomics (metatranscriptomics) retrieves and sequences environmental mRNAs from a microbial assemblage ...

Biyoloji

Obtaining High Quality RNA from Single Cell Populations in Human Postmortem Brain Tissue

We proposed to investigate the gray matter reduction in the superior temporal gyrus seen in schizophrenia patients, by interrogating gene expression profiles of pyramidal neurons in layer III. It is well known that the cerebral cortex is an exceptionally heterogeneous structure comprising diverse regions, layers and cell types, each of which is characterized by distinct cellular and molecular compositions and therefore differential gene expression profiles. To circumvent the confounding effects of tissue heterogeneity, we used laser-capture microdissection (LCM) in order to isolate our specific cell-type i.e pyramidal neurons.
Approximately 500 pyramidal neurons stained with the Histogene staining solution were captured using the Arcturus XT LCM system. RNA was then isolated from captured cells and underwent two rounds of T7-based linear amplification using Arcturus/Molecular Devices kits. The Experion LabChip (Bio-Rad) gel and electropherogram indicated good quality a(m)RNA, with a transcript length extending past 600nt required for microarrays. The amount of mRNA obtained averaged 51&mu;g, with acceptable mean sample purity as indicated by the A260/280 ratio, of 2.5. Gene expression was profiled using the Human X3P GeneChip probe array from Affymetrix.

We describe a process using laser-capture microdissection to isolate and extract RNA from a homogeneous cell population, pyramidal neurons, in layer III of the superior temporal gyrus in postmortem human brains. We subsequently linearly amplify (T7-based) mRNA, and hybridize the sample to the Affymetrix human X3P microarray.

İnsan Postmortem Beyin Dokusu Tek Hücre Popülasyonlar Yüksek Kalite RNA Alınması

We proposed to investigate the gray matter reduction in the superior temporal gyrus seen in schizophrenia patients, by interrogating gene expression ...

Multiplexed Single Cell mRNA Sequencing Analysis of Mouse Embryonic Cells

Single cell mRNA sequencing has made significant progress in the last several years and has become an important tool in the field of developmental biology. It has been successfully used to identify rare cell populations, discover novel marker genes, and decode spatial and temporal developmental information. The single cell method has also evolved from the microfluidic based Fluidigm C1 technology to the droplet-based solutions in the last two to three years. Here we used the heart as an example to demonstrate how to profile the mouse embryonic tissue cells using the droplet based scRNA-Seq method. In addition, we have integrated two strategies into the workflow to profile multiple samples in a single experiment. Using one of the integrated methods, we have simultaneously profiled more than 9,000 cells from eight heart samples. These methods will be valuable to the developmental biology field by providing a cost-effective way to simultaneously profile single cells from different genetic backgrounds, developmental stages, or anatomical locations.

Here we presented a multiplexed single cell mRNA sequencing method to profile gene expression in mouse embryonic tissues. The droplet-based single cell mRNA sequencing (scRNA-Seq) method in combination with multiplexing strategies can profile single cells from multiple samples simultaneously, which significantly reduces reagent costs and minimizes experimental batch effects.

Fare Embriyonik Hücrelerinin Çok katlı Tek Hücreli mRNA Sıralama Analizi

Single cell mRNA sequencing has made significant progress in the last several years and has become an important tool in the field of developmental ...

Gelişim Biyolojisi

Probing RNA Structure with Dimethyl Sulfate Mutational Profiling with Sequencing In Vitro and in Cells

The role of RNA structure in virtually any biological process has become increasingly evident, especially in the past decade. However, classical approaches to solving RNA structure, such as RNA crystallography or cryo-EM, have failed to keep up with the rapidly evolving field and the need for high-throughput solutions. Mutational profiling with sequencing using dimethyl sulfate (DMS) MaPseq is a sequencing-based approach to infer the RNA structure from a base&#39;s reactivity with DMS. DMS methylates the N1 nitrogen in adenosines and the N3 in cytosines at their Watson-Crick face when the base is unpaired. Reverse-transcribing the modified RNA with the thermostable group II intron reverse transcriptase (TGIRT-III) leads to the methylated bases being incorporated as mutations into the cDNA. When sequencing the resulting cDNA and mapping it back to a reference transcript, the relative mutation rates for each base are indicative of the base&#39;s &#34;status&#34; as paired or unpaired. Even though DMS reactivities have a high signal-to-noise ratio both in vitro and in cells, this method is sensitive to bias in the handling procedures. To reduce this bias, this paper provides a protocol for RNA treatment with DMS in cells and with in vitro transcribed RNA.

Probing RNA Structure with Dimethyl Sulfate Mutational Profiling with Sequencing In Vitro and in Cells

The protocol provides instruction for modifying RNA with dimethyl sulfate for mutational profiling experiments. It includes in vitro and in vivo probing with two alternative library preparation methods.

RNA Yapısının Dimetil Sülfat Mutasyonel Profillemesi ile İn Vitro ve İn Hücre Dizilimi ile İncelenmesi

The role of RNA structure in virtually any biological process has become increasingly evident, especially in the past decade. However, classical ...

Biyokimya

Single Cell Multiplex Reverse Transcription Polymerase Chain Reaction After Patch-clamp

The cerebral cortex is composed of numerous cell types exhibiting various morphological, physiological, and molecular features. This diversity hampers easy identification and characterization of these cell types, prerequisites to study their specific functions. This article describes the multiplex single cell reverse transcription polymerase chain reaction (RT-PCR) protocol, which allows, after patch-clamp recording in slices, to detect simultaneously the expression of tens of genes in a single cell. This simple method can be implemented with morphological characterization and is widely applicable to determine the phenotypic traits of various cell types and their particular cellular environment, such as in the vicinity of blood vessels. The principle of this protocol is to record a cell with the patch-clamp technique, to harvest and reverse transcribe its cytoplasmic content, and to detect qualitatively the expression of a predefined set of genes by multiplex PCR. It requires a careful design of PCR primers and intracellular patch-clamp solution compatible with RT-PCR. To ensure a selective and reliable transcript detection, this technique also requires appropriate controls from cytoplasm harvesting to amplification steps. Although precautions discussed here must be strictly followed, virtually any electrophysiological laboratory can use the multiplex single cell RT-PCR technique.

This protocol describes the critical steps and precautions required to perform single cell multiplex reverse transcription polymerase chain reaction after patch-clamp. This technique is a simple and effective method to analyze the expression profile of a predetermined set of genes from a single cell characterized by patch-clamp recordings.

Tek hücre Multiplex Ters transkripsiyon polimeraz zincir tepkimesi sonra yama-kelepçe

The cerebral cortex is composed of numerous cell types exhibiting various morphological, physiological, and molecular features. This diversity hampers ...

Laser Microdissection for Species-Agnostic Single-Tissue Applications

Single-cell methodologies have revolutionized the analysis of the transcriptomes of specific cell types. However, they often require species-specific genetic &#34;toolkits,&#34; such as promoters driving tissue-specific expression of fluorescent proteins. Further, protocols that disrupt tissues to isolate individual cells remove cells from their native environment (e.g., signaling from neighbors) and may result in stress responses or other differences from native gene expression states. In the present protocol, laser microdissection (LMD) is optimized to isolate individual nematode tail tips for the study of gene expression during male tail tip morphogenesis.
LMD allows the isolation of a portion of the animal without the need for cellular disruption or species-specific toolkits and is thus applicable to any species. Subsequently, single-cell RNA-seq library preparation protocols such as CEL-Seq2 can be applied to LMD-isolated single tissues and analyzed using standard pipelines, given that a well-annotated genome or transcriptome is available for the species. Such data can be used to establish how conserved or different the transcriptomes are that underlie the development of that tissue in different species.
Limitations include the ability to cut out the tissue of interest and the sample size. A power analysis shows that as few as 70 tail tips per condition are required for 80% power. Tight synchronization of development is needed to obtain this number of animals at the same developmental stage. Thus, a method to synchronize animals at 1 h intervals is also described.

A protocol is described that uses laser microdissection to isolate individual nematode tissues for RNA-sequencing. The protocol does not require species-specific genetic toolkits, allowing gene expression profiles to be compared between different species at the level of single-tissue samples.

Türlerden Agnostik Tek Doku Uygulamaları için Lazer Mikrodiseksiyonu

Single-cell methodologies have revolutionized the analysis of the transcriptomes of specific cell types. However, they often require species-specific ...