Name: a versatile method of patterning proteins and cells
Uploaded: 2017-02-26T15:00:00.000+00:00
Duration: 9 min 57 s
Description: Watch this Scientific Journal Video about A Versatile Method of Patterning Proteins and Cells at JoVE.com

Bu araştırma için finansman (FHK için) Omurilik Araştırma (NJCSCR) New Jersey Komisyonu tarafından sağlanan, (BLF için) CSCR14IRG005 hibe NIH (ÇHC için) R15NS087501 ve (ETA için) FM Kirby Vakfı hibe.

NOT: Kullanmadan önce tüm ilgili malzeme güvenlik bilgi formlarını (MSDS) danışın. Bu protokolde kullanılan kimyasalların bazıları toksik ve kanserojendir. toksik veya asit / baz malzemeleri kullanarak tüm uygun güvenlik uygulamaları (davlumbaz, torpido gözü) ve kişisel koruyucu donanımlar (koruyucu gözlük, eldiven, laboratuvar önlüğü, tam uzunlukta pantolon, kapalı-toe ayakkabılar) kullanın. Yumuşak Litografi kullanarak fotolitografi Master Kalıpları 1. Fabrikasyon <ol><li> bilgisayar destekli tasarım (CAD) çizim aracını kullanarak mikrokanalın düzenini çizin. </li><li> Lazer maske yazıcı kullanarak boş bir maske plaka üzerinde düzeni yazdırın. </li><li> solvent gofret bırakılır sağlamak için bir azot, hava tabancası ile izopropanol ve kuru ardından aseton ile 4 inçlik silikon gofret durulayın. </li><li> 5 dakika boyunca 200 ° C&#39;de sıcak bir plaka üzerinde pişirme gofretin kurutmak. </li><li> mikrokanalların istenilen yükseklikte için tasarlanmış bir negatif ışığa seçin. Fveya örneğin, 50 um arasında bir yüksekliğe sahip mikrokanallar elde etmek için negatif fotorezist SU-8 50 kullanımı. </li><li> gofret oda sıcaklığına soğumasını bekleyin ve sonra spin kaplayıcı aynanın üzerinde gofret hizalayın. </li><li> gofretin merkezi üzerine olumsuz bir fotorezist 4 mL (gofret 1 mL / inç çapında) koyun. </li><li> Bir eğiren kullanarak iki aşamalı bir sıkma ile kaplamaz gofret Spin. İlk olarak, 10 saniye boyunca 100 rpm / s bir ivme ile 500 rpm yayılma döngüsü uygulayın. Daha sonra gofret Fotorezist 50 um kaplama elde etmek için 30 saniyeden 300 dev / S2 bir ivme ile 2,000 rpm&#39;de bir sıkma işlemi uygulamak. </li><li> Yumuşak fırında, üretici firmanın talimatlarına uygun olarak sıcak bir plaka üzerinde, iki adımda gofret. Fotorezist 50 um kaplama, birinci ön-Bake 6 dakika boyunca 65 ° C &#39;de gofret ve sonra hemen 20 dakika süreyle 95 ° C de gofret fırında yayınlamak için sıcak levha sıcaklığı kadar rampa. </li><li> Gofret, oda sıcaklığına kadar soğumaya bırakıldı ve daha sonra yük Verenlitografi sahneye gofret. </li><li> Maske hizalama kullanarak gofret maske hizalayın ve 220 mJ toplam UV dozu uygulamak için 146 s için 1,5 mW / cm 2 &#39;lik bir yoğunlukta (üreticinin talimatlarına göre) UV ışığına maruz gofret / cm 2 için gerekli fotorezist 50 mikron kalınlığında tabaka. </li><li> sıcak bir plaka üzerinde iki adımda gofret sonrası maruz kalma fırında uygulayın. Fotorezist 50 mikron kaplama, birinci ön-Bake hemen 1 dakika boyunca 65 ° C sıcaklıkta, gofretin 5 dakika boyunca 95 ° C &#39;de fırında yayınlamak için sıcak levha sıcaklığı kadar rampa. </li><li> SU-8 geliştirici gofret daldırarak ve özellikleri gofret net hale gelene kadar hafifçe sallayarak gofret gelişir. 50 mikron kalınlığında paslanmaz çeliğin için ~ 6 dakika gofret geliştirin. </li><li> izopropanol ve etanol ile aşırı geliştirici durulayın, daha sonra bir azot hava tabancası ile gofret kurulayın. </li><li> Sert 15 dakika boyunca 150 ° C&#39;de bir sıcak plaka üzerinde silikon gofret fırında. </li><li> YeriSilanizing madde 25 uL bir kurutucuda gofret tridekaflor-1,1,2,2-tetrahydrooctyl-1-trichlorosilane. NOT: Silanizing ajan uygun kişisel koruyucu ekipman ile, böylece bir asit / baz davlumbaz kullanılması gerektiğini, aşındırıcı olan (koruyucu gözlük, eldiven, laboratuvar önlüğü, tam uzunlukta pantolon, ayakkabı-ayak kapalı). </li><li> 5 dakika boyunca vakum uygulayın ve vakum bırakmadan 30 dakika boyunca silan buharına gofret maruz bırakmaktadır. </li><li> Uygun büyüklükteki bir Petri kabı içine gofret aktarın. </li></ol> Yapıştırıcı Bant kullanarak, Yumuşak Litografi Master Kalıpları 2. Fabrikasyon <ol><li> Bir CAD çizim aracını kullanarak mikrokanalın düzenini çizin ve beyaz kağıda Çizimi yazdırmak. </li><li> izopropanol ile tasarım karşılamak ve daha sonra bir hava tabancası ile slayt kuruması için yeterli büyüklükte bir cam slayt temizleyin. </li><li> temizlenmiş cam slayt üzerine yapışkan bant takın. Herhangi bir hava kabarcıkları tuzak dikkatli olun. </li><li> GLA kenarlarını bantlayınss bant tarafı yukarı gelecek şekilde, tasarımı ile kağıda doğru kaydırın. </li><li> bir referans olarak kağıt tasarımını kullanarak cam slayt bandı kesmek ve daha sonra cam slayt istenmeyen bölgelerden şeridi sıyırın için bir neşter kullanın. </li><li> hava tabancası ile cam izopropanol ile slayt ve daha sonra kuru durulayın. 30 dakika boyunca 65 ° C sıcaklıkta bir fırın içinde cam slayt pişirin. </li><li> Yavaşça hava kabarcıklarını çıkarmak ve slayt oda sıcaklığına soğuması için bir kauçuk rulo ile bant üzerinde rulo. </li></ol> PDMS Cihazlarının 3. Yumuşak Litografi İmalatı <ol><li> 10 oranında PDMS elastomer ve sertleştirme ajanı karıştırılır: 1 (ağ: ağ), kuvvetli bir şekilde karıştırıldıktan ve herhangi bir hava kabarcığı karışım görünene kadar daha sonra bir vakum odası içine yerleştirerek karışım gaz çıkışına. </li><li> kabarcıklar kaybolur tüm hava kadar ~ 2 mm kalınlığında PDMS katman ve gazını elde etmek için bir petri bir Silanlanmış silikon kalıp veya yapışkan bant kalıp üzerine karışımı dökün. </li><li> bir fırın içinde PDMS Cure2 saat boyunca 65 ° C&#39;de. </li><li> en az 5 mm uzakta özelliklerinden PDMS katmanı kesmek için bir neşter kullanın ve sonra cımbız kullanarak kalıp kapalı tedavi PDMS soyun. </li><li> Şekil 2a görüldüğü ve 4b olarak 1 mm biyopsisi ile tek bir giriş deliği tercihen mikrokanallar ağı sonunda, mikrokanalda üzerinde herhangi bir yere yumruk yumruk. </li><li> cihazın üzerine adsorbe toz parçacıklarını çıkarmak için yapışkan bant ile dökme PDMS temizleyin. Steril deiyonize (Dİ) su ve ardından% 70 etanol çözeltisi ile durulama ile PDMS mikrokanal cihazı (PDMS döküm) sterilize ve 30 dakika boyunca UV maruz kalmaktadır. </li><li> kullanılana kadar steril bir petri steril PDMS cihaz tutun. </li></ol> 4. Yüzey Desenlendirme <ol><li> steril cam lamel veya petri üzerine cımbız kullanarak döküm steril PDMS yerleştirin ve cımbız ucunu kullanarak hafifçe baskı uygulayın. NOT: PDMS döküm gl bir konformal ama geri dönüşümlü mühür yapareşek lamel veya yapışkan kullanılmadan mikrokanallar oluşturan petri. </li><li> Tamamen giriş deliğini kaplayan girişindeki substrat çözeltisi - (40 uL 20) bir damlacık yerleştirin. mikrokanalların girişine sodyum tetraborat tamponunda PDL 20 uL damlacık koyarak Desen Poly-D-Lizin (PDL). </li><li> 10 dakika süre ile (biyolojik laboratuarlarda vakum ev eşdeğer) ve kabarcıklar halinde kanalın üzerinden gelen hava dikkate ~ 254 mmHgA bir vakumla petri koyun. </li><li> vakumu boşaltmak ve Mikrokanallı akan substrat solüsyonu gözlemleyin. </li><li> Yüzey yapışması için uygun şartlarda çanak inkübe edin. Tablo 1 ve inkübasyon koşulları için 2 (bunlar yüzeye bağlı olarak değişir) bakın. PDL desen için, 37 ° C &#39;de 1 saat süre ile inkübe edilir. </li><li> Dikkatle steril cımbız kullanarak PDMS damga soyulabilir ve DI su ile üç kere cam lamel üzerine desen yıkayın. </li&gt; <li> çanak, cam lamel kapak ve bir gece boyunca 37 ° C inkübe edilmesi petri bir% 1 sığır serum albümini (BSA) solüsyonu ekleyin. Not: Bu kaplanmamış bölgelerinde spesifik olmayan yapışmayı azaltır. </li><li> % 1 BSA çözeltisi ve desenli substrat kapalı aspire şimdi kullanıma hazırdır. </li></ol> Hücreleri 5. Dolaylı Desen <ol><li> serumsuz bir kültür ortamı içinde hücre süspansiyonu hazırlamak. Hücre tipi, hücre yoğunluğu, Tablo 1 &#39;de listelenmiştir. </li><li> desenli Petri kabı hücre süspansiyonu ekleyin ve tamamen hücre süspansiyonu desenli bölgeyi daldırın. </li><li> Hücreler desenli alt-tabakaya bağlamak için izin vermek için 15 dakika için bir kuluçka makinesi içinde 37 ° C &#39;de petri inkübe edin. </li><li> Petri kabı aşırı hücre süspansiyonu aspire ve yavaşça birleşmeyen hücrelerin çıkarılması için 10 saniye boyunca çalkalarken fosfat tamponlu tuzlu su (PBS) ile desenli hücreler üç kez yıkayın. </li><li> a ekleppropriate kültürü desenli hücre kültürlerine orta ve bir CO2 inkübatör içinde 37 ° C &#39;de desenli hücreleri inkübe edin. </li></ol> Hücreleri 6. Doğrudan Desen NOT: Bu teknik, hücreler ya da alt-tabaka kaplaması olmayan doku kültür yüzeyleri üzerinde desenli Bu teknikte, 5. adımda farklı olarak aşama 5&#39;te tarif dolaylı hücre dokusuna bir alternatiftir. <ol><li> DI su, ardından etanol içinde% 70 çözeltisi ile durulama ile mikroakışkan cihaz sterilize edin. </li><li> PDMS hücre yapışmasını önlemek için% 1 BSA çözeltisi gece boyunca cihazı bekletin. </li><li> Oda sıcaklığında cihazı kurutun ve doku kültürü ile tedavi petri altına ekleyin. </li><li> serumsuz kültür ortamı içinde hücre süspansiyonu hazırlamak. Hücre tipi, hücre yoğunluğu, Tablo 2&#39;de sıralanmıştır. </li><li> doldurmak için yeterli hücre süspansiyonu - (8 uL 4), bir damlacık yerleştirinmikrokanallar, giriş tamamen giriş deliğini kaplayan. </li><li> 10 dakika boyunca vakumla petri koyun ve kabarcıklar halinde kanalın üzerinden gelen hava dikkate alınmalıdır. vakumu boşaltmak ve Mikrokanallı akan hücre süspansiyonu gözlemleyin. </li><li> Kuluçka şartlarına göre hücre yapışmasını teşvik etmek bir kuluçka Petri kabı inkübe Tablo 2&#39;de belirtilen (hücrenin desenli tipine bağlıdır). PDMS cihaz daldırarak petri PBS ekleyin. </li><li> Peel PDMS dikkatle cımbız ile petri kapalı ve PBS ile desen yıkayın. Petri kabı, hücre kültür ortamı ekleyin ve inkübatör hücre kültürü yerleştirin. </li></ol>

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D., Pinnau, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gas+sorption,+diffusion,+and+permeation+in+poly(dimethylsiloxane).">Gas sorption, diffusion, and permeation in poly(dimethylsiloxane).</a> J Polym Sci Part B Polym Phys. 38 (3), 415-434 (2000).</li><li>Shrirao, A. B., Hussain, A., Cho, C. H., Perez-Castillejos, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adhesive-tape+soft+lithography+for+patterning+mammalian+cells:+application+to+wound-healing+assays.">Adhesive-tape soft lithography for patterning mammalian cells: application to wound-healing assays.</a> Biotechniques. 53 (5), 315-318 (2012).</li><li>Shrirao, A. B., Perez-Castillejos, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chips+&amp;+tips:+simple+fabrication+of+microfluidic+devices+by+replicating+scotch-tape+masters.">Chips &amp; tips: simple fabrication of microfluidic devices by replicating scotch-tape masters.</a> Lab Chip. , (2010).</li><li>Anil, B. S., Frank, H. K., Derek, Y., Cheul, H. C., Ellen, T. -. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vacuum-assisted+fluid+flow+in+microchannels+to+pattern+substrates+and+cells.">Vacuum-assisted fluid flow in microchannels to pattern substrates and cells.</a> Biofabrication. 6 (3), 035016 (2014).</li><li>Yuen, P. K., Goral, V. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Low-cost+rapid+prototyping+of+flexible+microfluidic+devices+using+a+desktop+digital+craft+cutter.">Low-cost rapid prototyping of flexible microfluidic devices using a desktop digital craft cutter.</a> Lab on a Chip. 10 (3), 384-387 (2010).</li><li>Wang, L., 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=Self-loading+and+cell+culture+in+one+layer+microfluidic+devices.">Self-loading and cell culture in one layer microfluidic devices.</a> Biomed Microdevices. 11 (3), 679-684 (2009).</li><li>Feng, H., 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=Survival+of+mammalian+cells+under+high+vacuum+condition+for+ion+bombardment.">Survival of mammalian cells under high vacuum condition for ion bombardment.</a> Cryobiology. 49 (3), 241-249 (2004).</li><li>Haubert, K., Drier, T., Beebe, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=PDMS+bonding+by+means+of+a+portable,+low-cost+corona+system.">PDMS bonding by means of a portable, low-cost corona system.</a> Lab on a Chip. 6 (12), 1548-1549 (2006).</li><li>Fan, D. -. H., Yuan, S. -. W., Shen, Y. -. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surface+modification+with+BSA+blocking+based+on+in+situ+synthesized+gold+nanoparticles+in+poly+(dimethylsiloxane)+microchip.">Surface modification with BSA blocking based on in situ synthesized gold nanoparticles in poly (dimethylsiloxane) microchip.</a> Colloids Surf, B. 75 (2), 608-611 (2010).</li><li>Hideshima, S., Sato, R., Inoue, S., Kuroiwa, S., Osaka, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detection+of+tumor+marker+in+blood+serum+using+antibody-modified+field+effect+transistor+with+optimized+BSA+blocking.">Detection of tumor marker in blood serum using antibody-modified field effect transistor with optimized BSA blocking.</a> Sens Actuator B-Chem. 161 (1), 146-150 (2012).</li><li>Zheng, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-throughput+immunoassay+through+in-channel+microfluidic+patterning.">High-throughput immunoassay through in-channel microfluidic patterning.</a> Lab on a Chip. 12 (14), 2487-2490 (2012).</li><li>MacLeish, P., Barnstable, C., Townes-Anderson, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+a+monoclonal+antibody+as+a+substrate+for+mature+neurons+in+vitro.">Use of a monoclonal antibody as a substrate for mature neurons in vitro.</a> Procs Nat Acad of Sci. 80 (22), 7014-7018 (1983).</li><li>Suchodolskis, A., 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=Elastic+properties+of+chemically+modified+baker's+yeast+cells+studied+by+AFM.">Elastic properties of chemically modified baker's yeast cells studied by AFM.</a> Surf Interface Anal. 43 (13), 1636-1640 (2011).</li></ol>

The authors declare no competing financial interests.

Geleneksel fotolitografi yumuşak litografi, ekipman, malzeme ve geleneksel fotolitografi kullanmak için gerekli becerileri için kalıplar oluşturulması için köklü bir tekniktir iken en laboratuarlara hazır değildir. Bu kaynaklara erişimi olmayan laboratuarlar için, mikroakışkan cihazlar için nispeten basit özelliklere sahip kalıplar oluşturma yöntemi olarak yapışkan bant imalat sunduk. Bu yöntem, herhangi bir laboratuvar oluşturmak ve hazır araçları ile araştırma amacıyla mikroakışkan ciha...

Doku mühendisliği ve biosensörleme, bir mikron ölçeğinde proteinleri ve hücreleri mekansal organizasyonu kontrol etme yeteneği, son dört yılda 1, 2, 3 üzerinde giderek daha önemli hale gelmiştir. Protein ve hücrelerin hassas mekansal organizasyon, araştırmacılar, hücre büyümesini yol ve biyosensörler 4, 5, 6, 7, 8, üretim için biyomoleküllerin hareketsiz hale getirmek için, hücrelerin benzer ya da farklı türlerini içeren hücreler ve alt tabakalar arasındaki etkileşimi incelemek sağladı 9. desen proteinlerinin Mevcut yöntemler photopatterning ve microcontact baskı bulunmaktadır. Photopatterning ultr maruz kalması üzerine çapraz bağlanır ışığa duyarlı malzeme kullanılanmor (UV) ışık. (UV ışığı iletim önlemek için daha koyu bölgeler saydam alanlarında oluşan) bir fotomaske yönelik UV ışığı daha sonra biyo veya hücre 10, 11 daha sonra eklenmesi için kullanılabilen belirli bölgelerde çapraz bağlama neden olur. Bu düzeni çok doğru ve kültür yüzey topografyasının hassas kontrol sağlar, UV radyasyonu 12 ile desenli olabilir UV duyarlı biyomoleküllerin sınırlıdır. Microcontact baskı özel proteinler 13, 14 desenlendirme başka popüler bir yöntemdir. Bu yöntemde, bir poli-dimetil siloksan (PDMS) Pul seçilen biyomoleküler alt-tabakanın bir çözelti içinde ıslatılan önce yüzey değiştirme reaktifler çeşitli ile işlenir. Daha sonra yavaşça ve böylece, kültür yüzey üzerine biyomolekülün &quot;damgalama&quot; cam lamel veya diğer yüzeyi üzerine bastırılmaktadır. HoWever, damgalama PDMS 15 damga yüzeyine biyomoleküllerin ıslanabilirliği hem de aktarılabilir malzemenin türüne sınırlıdır. Hücrelerin doğrudan desen daha zor olabilir ve bu özel hücre yapışma molekülleri 16, 17 ile değiştirilebilir alt tabakalar, Şablon göre yöntem ya da desen gibi karmaşık yöntemle gerçekleştirilir olabilir. Bu yöntemler sayesinde uyumlu hücre yapışma yüzeylerde eksikliği desen hücrelerine yetenekleri sınırlıdır, sürecin uyumsuzluk duyarlı biyolojik hücreler ve kısıtlamaları, desenlendirme üreyen tutarsızlık ve prosedürün karmaşıklığı ile çalışmak. Örneğin, değiştirilebilir yüzeyler ile özel yüzeyler &lt;sürecinde 17 kullanılan UV ışınlarına ve ısıya maruz kalma üzerine bozulma olmadan belirli hücre tiplerine bağlılıklarını geçmek için, her hücre tipi için tasarlanmış olması gerekir<html> sup class = &quot;xref&quot;&gt; 18, 19, 20. Stencil tabanlı desenlendirme yöntemleri desen hücrelerine yeteneklerini çok yönlü; Bununla birlikte, kullanım 16, 21 için uygun kalınlıklarda PDMS kalıpları üretmek zordur. 1) mikroakışkan kanalların üretiminde kolaylığı ve birçok farklı hücre ve yüzeyler için 2) uygunluk: PDMS mikroakışkan kanal içine hücrelerin direkt enjeksiyon bazı avantajlar gibi var. Ancak, hava kabarcıklarını azaltmak için plazma temizleme ya da diğer yöntemleri kullanmadan PDMS hidrofobiklik enjeksiyon işlemi sırasında hava kabarcığı yakalama yaygın sorun, zor sürekli cam veya plastik yüzeylerde 21 desenli hücreleri oluşturmayı kolaylaştırır. Bu eser, kılcal micromolding 22, 23 genişliyorlass = &quot;xref&quot;&gt; 24, 25, 26 ve mikro halinde protein ve hücre süspansiyonları enjekte etmek için bir metodu bildirir. Burada kullanılan yöntem yüzeylerde desenlendirme ve spesifik hücre tiplerinin her ikisi de doğrudan ve dolaylı desenlendirme göstermektedir. Bu teknik, PDMS yüksek hidrofobikliğini üstesinden gelir ve PDMS 27 gaz geçirgenliği yararlanarak iki alt tabakaların veya hücre enjeksiyonu sırasında kabarcıkların mevcudiyetini ortadan kaldırır. Bu çalışma, birçok farklı alt-tabaka ve hücre tipleri ile tekniğin kullanımını gösterir. Makalede ayrıca, geleneksel fotolitografi yanı sıra kaynak kullanışlı, basit ve düşük maliyetli yapışkan bant yöntemi sınırlı ayarlar 28, 29 kullanılarak yumuşak litografi için kalıp imalat vurgulamaktadır.

<table><tbody><tr><td>CorelDRAW X4 CAD Drawing Tools</td><td>Corel Corporation, Canada</td><td>X4 Version 14.0.0.701</td><td>CAD tool used to draw the layout of the microfluidic device</td></tr><tr><td>Laser Printer HP</td><td>Hewlett Packard, CA</td><td>1739629</td><td>Used to print the layout of microfluidic device for adhesive tape technique</td></tr><tr><td>Bel-Art Dessicator</td><td>Fisher Scientific, MA</td><td>08-594-16B</td><td>Used to degass the PDMS mixture</td></tr><tr><td>Adhesive Scotch Tape</td><td>3M Product, MN</td><td>Tape 600</td><td>Used to fabricate adhesive tape Master</td></tr><tr><td>PDMS Sylgard 184</td><td>Dow Corning, MI</td><td>1064291</td><td>Casting polymer</td></tr><tr><td>Petri Dish</td><td>Fisher Scientific, MA</td><td>08-772-23</td><td>Used to keep the mold to cast with PDMS</td></tr><tr><td>Stainless steel Scalpel (#3) with blade (# 11)</td><td>Feather Safety Razor Co. Ltd. Japan</td><td>2976#11</td><td>Used to cut the PDMS</td></tr><tr><td>Tweezers</td><td>Ted Pella, CA</td><td>5627-07</td><td>Used to handle the PDMS cast during peeling</td></tr><tr><td>Glass slides</td><td>Fisher Scientific, MA</td><td>12-546-2</td><td>Used as surface to pattern the Substrate</td></tr><tr><td>Glass slides</td><td>Fisher Scientific, MA</td><td>12-544-4</td><td>Used as surface to pattern the Substrate</td></tr><tr><td>Rubber Roller</td><td>Dick Blick Art Materials, IL</td><td>40104-1004</td><td>Used to attach adhesive tape on glass without trapping air bubbles</td></tr><tr><td>Laser Mask Writer</td><td>Heidelberg Instruments, Germany</td><td>DWL66fs</td><td>Used to fabricate quartz mask used in photolithography fabrication process</td></tr><tr><td>EVG Mask Aligner (Photolithography UV exposure tool)</td><td>EV Group, Germany</td><td>EVG 620T(B)</td><td>Used to expose the photoresist to UV light</td></tr><tr><td>Spin Coater Headway</td><td>Headway Research Inc, TX</td><td>PWM32-PS-CB15PL</td><td>Used to spin coat the photoresist on silicon wafer</td></tr><tr><td>Photoresists SU-8 50</td><td>MicroChem, MA</td><td>Y131269</td><td>Negative photoresist used for mold fabrication</td></tr><tr><td>SU-8 Devloper</td><td>MicroChem, MA</td><td>Y020100</td><td>Photoresist developer</td></tr><tr><td>Tridecafluoro-1,1,2,2-Tetrahydrooctyl-1-Trichlorosilane</td><td>UCT Specialties, PA</td><td>T2492-KG</td><td>Coat mold to avoid PDMS adhesion</td></tr><tr><td>Isopropanol</td><td>Sigma-Aldrich, MO</td><td>190764</td><td>Cleaning Solvent</td></tr><tr><td>Ethanol</td><td>Sigma-Aldrich, MO</td><td>24102</td><td>Sterilization Solvent</td></tr><tr><td>Poly-D-Lysine hydrobromide (PDL)</td><td>Sigma-Aldrich, MO</td><td>P0899-10MG</td><td>PDL solution is made at 0.1 mg/mL in Sodium Tetraborate Buffer</td></tr><tr><td>Laminin</td><td>Sigma-Aldrich, MO</td><td>L2020</td><td>Laminin aliquoted into 10 &amp;micro;L aliquots and diluted to 20 &amp;micro;g/&amp;micro;L in PBS prior to use</td></tr><tr><td>BSA</td><td>Fisher Scientific, MA</td><td>BP1605100</td><td>Cell culture</td></tr><tr><td>C2C12 Myoblast cell lline</td><td>ATCC, VA</td><td>CRL-1722</td><td>Used to demonstrate C2C12 patterning</td></tr><tr><td>PC12 Cell Line</td><td>ATCC, VA</td><td>CRL-1721</td><td>Used to demonstrate PC12 patterning</td></tr><tr><td>Collagen type 1, rat tail</td><td>BD Biosciences</td><td>40236</td><td>Cell culture</td></tr><tr><td>DMEM</td><td>GIBCO, MA</td><td>11965-084</td><td>Cell culture</td></tr><tr><td>Horse Serum, heat inactivated</td><td>Fisher Scientific, MA</td><td>26050-070</td><td>Cell culture</td></tr><tr><td>Phalloidin-tetramethylrhodamine B isothiocyanate (TRITC)</td><td>Sigma-Aldrich, MO</td><td>P1951</td><td>To label cells</td></tr><tr><td>Calcein-AM live dead cell Assay kit</td><td>Invitrogen, MA</td><td>L-3224</td><td>Cell viability Assay</td></tr><tr><td>Biopsy Hole Punch</td><td>Ted Pella, CA</td><td>15110-10</td><td>Punched hole in PDMS</td></tr></tbody></table>

a versatile method of patterning proteins and cells

Substrate and cell patterning techniques are widely used in cell biology to study cell-to-cell and cell-to-substrate interactions. Conventional patterning techniques work well only with simple shapes, small areas and selected bio-materials. This article describes a method to distribute cell suspensions as well as substrate solutions into complex, long, closed (dead-end) polydimethylsiloxane (PDMS) microchannels using negative pressure. This method enables researchers to pattern multiple substrates including fibronectin, collagen, antibodies (Sal-1), poly-D-lysine (PDL), and laminin. Patterning of substrates allows one to indirectly pattern a variety of cells. We have tested C2C12 myoblasts, the PC12 neuronal cell line, embryonic rat cortical neurons, and amphibian retinal neurons. In addition, we demonstrate that this technique can directly pattern fibroblasts in microfluidic channels via brief application of a low vacuum on cell suspensions. The low vacuum does not significantly decrease cell viability as shown by cell viability assays. Modifications are discussed for application of the method to different cell and substrate types. This technique allows researchers to pattern cells and proteins in specific patterns without the need for exotic materials or equipment and can be done in any laboratory with a vacuum.

Bu yöntem proteinleri ve ana kalıp yapıldıktan sonra neredeyse tüm biyolojik laboratuarlarda 10 um ve mevcut ekipman kadar küçük boyutlara sahip çıkmaz mikroakışkan kanalları kullanarak hücrelerin dolaylı desenlendirme desenlendirme sağlar. Bu teknik, geleneksel yumuşak fotolitografi veya yapışkan bant üretimi (Şekil 1) 28, 29 ile oluşturulan PDMS mikroakışkan kanalları ile kullanılarak ...

Watch this Scientific Journal Video about A Versatile Method of Patterning Proteins and Cells at JoVE.com

A Versatile Method of Patterning Proteins and Cells

This report describes a simple, easy to perform technique, using low pressure vacuum, to fill microfluidic channels with cells and substrates for biological research.

Desenlendirme Proteinlerin ve Hücreleri Çok Yönlü Yöntemi

Substrate and cell patterning techniques are widely used in cell biology to study cell-to-cell and cell-to-substrate interactions. Conventional patterning ...

a-versatile-method-of-patterning-proteins-and-cells

Research

JoVE Journal

Bioengineering

9.3K Görüntüleme.  Rutgers University. This report describes a simple, easy to perform technique, using low pressure vacuum, to fill microfluidic channels with cells and substrates for biological research.

Video: A Versatile Method of Patterning Proteins and Cells

Creating Two-Dimensional Patterned Substrates for Protein and Cell Confinement

Microcontact printing provides a rapid, highly reproducible method for the creation of well-defined patterned substrates.1 While microcontact printing can be employed to directly print a large number of molecules, including proteins,2 DNA,3 and silanes,4 the formation of self-assembled monolayers (SAMs) from long chain alkane thiols on gold provides a simple way to confine proteins and cells to specific patterns containing adhesive and resistant regions. This confinement can be used to control cell morphology and is useful for examining a variety of questions in protein and cell biology. Here, we describe a general method for the creation of well-defined protein patterns for cellular studies.5 This process involves three steps: the production of a patterned master using photolithography, the creation of a PDMS stamp, and microcontact printing of a gold-coated substrate. Once patterned, these cell culture substrates are capable of confining proteins and/or cells (primary cells or cell lines) to the pattern.
The use of self-assembled monolayer chemistry allows for precise control over the patterned protein/cell adhesive regions and non-adhesive regions; this cannot be achieved using direct protein stamping. Hexadecanethiol, the long chain alkane thiol used in the microcontact printing step, produces a hydrophobic surface that readily adsorbs protein from solution. The glycol-terminated thiol, used for backfilling the non-printed regions of the substrate, creates a monolayer that is resistant to protein adsorption and therefore cell growth.6 These thiol monomers produce highly structured monolayers that precisely define regions of the substrate that can support protein adsorption and cell growth. As a result, these substrates are useful for a wide variety of applications from the study of intercellular behavior7 to the creation of microelectronics.8
While other types of monolayer chemistry have been used for cell culture studies, including work from our group using trichlorosilanes to create patterns directly on glass substrates,9 patterned monolayers formed from alkane thiols on gold are straight-forward to prepare. Moreover, the monomers used for monolayer preparation are commercially available, stable, and do not require storage or handling under inert atmosphere. Patterned substrates prepared from alkane thiols can also be recycled and reused several times, maintaining cell confinement.10

Self-assembled monolayers (SAMs) formed from long chain alkane thiols on gold provide well-defined substrates for the formation of protein patterns and cell confinement. Microcontact printing of hexadecanethiol using a polydimethylsiloxane (PDMS) stamp followed by backfilling with a glycol-terminated alkane thiol monomer produces a pattern where protein and cells adsorb only to the stamped hexadecanethiol region.

Protein ve hücre Etrafının İki Boyutlu Desenli Yüzeyler Oluşturma

Microcontact printing provides a rapid, highly reproducible method for the creation of well-defined patterned substrates.1  While microcontact printing ...

Biyomühendislik

Patterning of Embryonic Stem Cells Using the Bio Flip Chip

Cell-cell interactions consisting of diffusible signaling and cell-cell contact (juxtacrine signaling) are important in numerous biological processes such as tumor growth, stem cell differentiation, and stem cell self-renewal. A number of methods currently exist to modulate cell signaling in vitro. One method of modulating the total amount of diffusible signaling is to vary the cell seeding density during culture. Due to the random nature of cell seeding, this results in considerable variation in the actual cell-cell spacing and amount of cell-cell contact, and cannot prescribe the local environment. A more specific approach for modulating cell signaling is to use molecular inhibitors or genetic approaches to knock down specific signaling proteins, but both of these methods are best suited to manipulating small numbers of molecules. Here, we demonstrate a new approach to modulating cell-cell signaling that modulates the local environment of a cluster of cells by placing different numbers of cells at desired locations on a substrate. This method provides a complementary way to control the local diffusible and juxtacrine signaling between cells. Our method makes use of the Bio Flip Chip (BFC), a microfabricated silicone chip containing hundreds-to-thousands of microwells, each sized to hold either a single cell or small numbers of cells. We load the chip with cells simply by pipetting them onto the array of wells and washing unloaded cells off the array. The chip is then flipped onto a substrate, whereby the cells fall out of the wells and onto the substrate, maintaining their patterning. After the cells have attached, the chip can be removed (or left on). This approach to cell patterning is unique in that it: 1) doesn't alter the chemistry of the substrate, thus allowing cells to proliferate and migrate; 2) allows patterning onto any substrate, including tissue-culture polystyrene, glass, matrigel, and even feeder cell layers; and 3) is compatible with traditional microcontact printing, allowing the creation of extracellular matrix islands with cells placed inside those islands. In this video, we demonstrate the patterning of mouse embryonic stem cells onto tissue-culture polystyrene using the BFC.

We demonstrate a simple method for placing cells at desired locations on a substrate. This method patterns cells by flipping a silicone chip containing microwells filled with cells onto the substrate. This method provides a new way to modulate diffusible and juxtacrine signaling between cells.

Bio Flip-Chip kullanarak Embriyonik Kök Hücreler, Desenlendirme

Cell-cell interactions consisting of diffusible signaling and cell-cell contact (juxtacrine signaling) are important in numerous biological processes such ...

Biyoloji

Cell Co-culture Patterning Using Aqueous Two-phase Systems

Cell patterning technologies that are fast, easy to use and affordable will be required for the future development of high throughput cell assays, platforms for studying cell-cell interactions and tissue engineered systems. This detailed protocol describes a method for generating co-cultures of cells using biocompatible solutions of dextran (DEX) and polyethylene glycol (PEG) that phase-separate when combined above threshold concentrations. Cells can be patterned in a variety of configurations using this method. Cell exclusion patterning can be performed by printing droplets of DEX on a substrate and covering them with a solution of PEG containing cells. The interfacial tension formed between the two polymer solutions causes cells to fall around the outside of the DEX droplet and form a circular clearing that can be used for migration assays. Cell islands can be patterned by dispensing a cell-rich DEX phase into a PEG solution or by covering the DEX droplet with a solution of PEG. Co-cultures can be formed directly by combining cell exclusion with DEX island patterning. These methods are compatible with a variety of liquid handling approaches, including manual micropipetting, and can be used with virtually any adherent cell type.

Aqueous two-phase systems were used to simultaneously pattern multiple populations of cells. This fast and easy method for cell patterning takes advantage of the phase separation of aqueous solutions of dextran and polyethylene glycol and the interfacial tension that exists between the two polymer solutions.

Sulu İki fazlı sistemler kullanma Hücre Co-kültür desenlendirme

Cell patterning  technologies that are fast, easy to use and affordable will be required for the  future development of high throughput cell assays, ...

Cell Patterning on Photolithographically Defined 
Parylene-C: SiO2 Substrates

Cell patterning platforms support broad research goals, such as construction of predefined in vitro neuronal networks and the exploration of certain central aspects of cellular physiology. To easily combine cell patterning with Multi-Electrode Arrays (MEAs) and silicon-based &#8216;lab on a chip&#8217; technologies, a microfabrication-compatible protocol is required. We describe a method that utilizes deposition of the polymer parylene-C on SiO2&#160;wafers. Photolithography enables accurate and reliable patterning of parylene-C at micron-level resolution. Subsequent activation by immersion in fetal bovine serum (or another specific activation solution) results in a substrate in which cultured cells adhere to, or are repulsed by, parylene or SiO2 regions respectively. This technique has allowed patterning of a broad range of cell types (including primary murine hippocampal cells, HEK 293 cell line, human neuron-like teratocarcinoma cell line, primary murine cerebellar granule cells, and primary human glioma-derived stem-like cells). Interestingly, however, the platform is not universal; reflecting the importance of cell-specific adhesion molecules. This cell patterning process is cost effective, reliable, and importantly can be incorporated into standard microfabrication (chip manufacturing) protocols, paving the way for integration of microelectronic technology.

Cell Patterning on Photolithographically Defined 
Parylene-C: SiO2 Substrates

This protocol describes a microfabrication-compatible method for cell patterning on SiO2. A predefined parylene-C design is photolithographically printed on SiO2 wafers. Following incubation with serum (or other activation solution) cells adhere specifically to (and grow according to the conformity of) underlying parylene-C, whilst being repulsed by SiO2 regions.

Photolithographically Tanımlı Parylene-C hücre Desenlendirme: SiO<sub&gt; 2</sub&gt; Yüzeyleri

Cell patterning platforms support broad research goals, such as construction of predefined in vitro neuronal networks and the exploration of certain ...

Microcontact Printing of Proteins for Cell Biology

The ability to pattern proteins and other biomolecules onto substrates is important for capturing the spatial complexity of the extracellular environment. Development of microcontact printing by the Whitesides group (<a href="http://gmwgroup.harvard.edu/">http://gmwgroup.harvard.edu/</a>) in the mid-1990s revolutionalized this field by making microelectronics/microfabrication techniques accessible to laboratories focused on the life sciences. Initial implementations of this method used polydimethylsiloxane (PDMS) stamps to create patterns of functionalized chemicals on material surfaces1. Since then, a range of innovative approaches have been developed to pattern other molecules, including proteins2. This video demonstrates the basic process of creating PDMS stamps and uses them to pattern proteins, as these steps are difficult to accurately express in words. We focus on patterning the extracellular matrix protein fibronectin onto glass coverslips as a specific example of patterning.
An important component of the microcontact printing process is a topological master, from which the stamps are cast; the raised and lowered regions of the master are mirrored into the stamp and define the final pattern. Typically, a master consists of a silicon wafer coated with photoresist and then patterned by photolithography, as is done here. Creation of masters containing a specific pattern requires specialized equipment, and is best approached in consultation with a fabrication center or facility. However, almost any substrate with topology can be used as a master, such as plastic diffraction gratings (see Reagents for one example), and such serendipitous masters provide readily available, simple patterns. This protocol begins at the point of having a master in hand.

Microcontact printing is used extensively to pattern proteins and other molecules on material surfaces. We demonstrate the basic steps of this process, stamping patterns of fibronectin onto glass.

Proteinlerin Hücre Biyolojisi Microcontact Baskı

The ability to pattern proteins and other biomolecules onto substrates is important for capturing the spatial complexity of the extracellular environment. ...

Mapping the Emergent Spatial Organization of Mammalian Cells using Micropatterns and Quantitative Imaging

A fundamental goal in biology is to understand how patterns emerge during development. Several groups have shown that patterning can be achieved in vitro when stem cells are spatially confined onto micropatterns, thus setting up experimental models which offer unique opportunities to identify, in vitro, the fundamental principles of biological organisation.
Here we describe our own implementation of the methodology. We adapted a photo-patterning technique to reduce the need for specialized equipment to make it easier to establish the method in a standard cell biology laboratory. We also developed a free, open-source and easy to install image analysis framework in order to precisely measure the preferential positioning of sub-populations of cells within colonies of standard shapes and sizes. This method makes it possible to reveal the existence of patterning events even in seemingly disorganized populations of cells. The technique provides quantitative insights and can be used to decouple influences of the environment (e.g., physical cues or endogenous signaling), on a given patterning process.

The method presented here uses micropatterning together with quantitative imaging to reveal spatial organization within mammalian cultures. The technique is easy to establish in a standard cell biology laboratory and offers a tractable system to study patterning in vitro.

Meme hücrelerinin Mikrodesenler ve nicel görüntüleme kullanarak acil uzamsal organizasyonu haritalama

A fundamental goal in biology is to understand how patterns emerge during development. Several groups have shown that patterning can be achieved in vitro ...

Gelişim Biyolojisi

Preparation of Tunable Extracellular Matrix Microenvironments to Evaluate Schwann Cell Phenotype Specification

Traumatic peripheral nervous system (PNS) injuries currently lack suitable treatments to regain full functional recovery. Schwann cells (SCs), as the major glial cells of the PNS, play a vital role in promoting PNS regeneration by dedifferentiating into a regenerative cell phenotype following injury. However, the dedifferentiated state of SCs is challenging to maintain through the time-period needed for regeneration and is impacted by changes in the surrounding extracellular matrix (ECM). Therefore, determining the complex interplay between SCs and differing ECM to provide cues of regenerative potential of SCs is essential. To address this, a strategy was created where different ECM proteins were adsorbed onto a tunable polydimethylsiloxane (PDMS) substrate which provided a platform where stiffness and protein composition can be modulated. SCs were seeded onto the tunable substrates and critical cellular functions representing the dynamics of SC phenotype were measured. To illustrate the interplay between SC protein expression and cellular morphology, differing seeding densities of SCs in addition to individual microcontact printed cellular patterns were utilized and characterized by immunofluorescence staining and western blot. Results showed that cells with a smaller spreading area and higher extent of cellular elongation promoted higher levels of SC regenerative phenotypic markers. This methodology not only begins to unravel the significant relationship between the ECM and cellular function of SCs, but also provides guidelines for the future optimization of biomaterials in peripheral nerve repair.

This methodology aims to illustrate the mechanisms by which extracellular matrix cues such as substrate stiffness, protein composition and cell morphology regulate Schwann cell (SC) phenotype.

Schwann Hücre Fenotip Spesifikasyonunu Değerlendirmek Için Hücre Dışı Matriks Mikroortamlarının Hazırlanması

Traumatic peripheral nervous system (PNS) injuries currently lack suitable treatments to regain full functional recovery. Schwann cells (SCs), as the ...

Simple, Affordable, and Modular Patterning of Cells using DNA

The relative positioning of cells is a key feature of the microenvironment that organizes cell-cell interactions. To study the interactions between cells of the same or different type, micropatterning techniques have proved useful. DNA Programmed Assembly of Cells (DPAC) is a micropatterning technique that targets the adhesion of cells to a substrate or other cells using DNA hybridization. The most basic operations in DPAC begin with decorating cell membranes with lipid-modified oligonucleotides, then flowing them over a substrate that has been patterned with complementary DNA sequences. Cells adhere selectively to the substrate only where they find a complementary DNA sequence. Non-adherent cells are washed away, revealing a pattern of adherent cells. Additional operations include further rounds of cell-substrate or cell-cell adhesion, as well as transferring the patterns formed by DPAC to an embedding hydrogel for long-term culture. Previously, methods for patterning oligonucleotides on surfaces and decorating cells with DNA sequences required specialized equipment and custom DNA synthesis, respectively. We report an updated version of the protocol, utilizing an inexpensive benchtop photolithography setup and commercially available cholesterol modified oligonucleotides (CMOs) deployed using a modular format. CMO-labeled cells adhere with high efficiency to DNA-patterned substrates. This approach can be used to pattern multiple cell types at once with high precision and to create arrays of microtissues embedded within an extracellular matrix. Advantages of this method include its high resolution, ability to embed cells into a three-dimensional microenvironment without disrupting the micropattern, and flexibility in patterning any cell type.

Here we present a protocol to micropattern cells at single-cell resolution using DNA-programmed adhesion. This protocol uses a benchtop photolithography platform to create patterns of DNA oligonucleotides on a glass slide and then labels cell membranes with commercially available complementary oligonucleotides. Hybridization of the oligos results in programmed cell adhesion.

DNA Kullanarak Hücrelerin Basit, Uygun Fiyatlı ve Modüler Deseni

The relative positioning of cells is a key feature of the microenvironment that organizes cell-cell interactions. To study the interactions between cells ...

Control of Cell Geometry through Infrared Laser Assisted Micropatterning

Micropatterning is an established technique in the cell biology community used to study connections between the morphology and function of cellular compartments while circumventing complications arising from natural cell-to-cell variations. To standardize cell shape, cells are either confined in 3D molds or controlled for adhesive geometry through adhesive islands. However, traditional micropatterning techniques based on photolithography and deep UV etching heavily depend on clean rooms or specialized equipment. Here we present an infrared laser assisted micropatterning technique (microphotopatterning) modified from Doyle et al. that can be conveniently set up with commercially available imaging systems. In this protocol, we use a Nikon A1R MP+ imaging system to generate micropatterns with micron precision through an infrared (IR) laser that ablates preset regions on poly-vinyl alcohol coated coverslips. We employ a custom script to enable automated pattern fabrication with high efficiency and accuracy in systems not equipped with a hardware autofocus. We show that this IR laser assisted micropatterning (microphotopatterning) protocol results in defined patterns to which cells attach exclusively and take on the desired shape. Furthermore, data from a large number of cells can be averaged due to the standardization of cell shape. Patterns generated with this protocol, combined with high resolution imaging and quantitative analysis, can be used for relatively high throughput screens to identify molecular players mediating the link between form and function.

The protocol presented here enables automated fabrication of micropatterns that standardizes cell shape to study cytoskeletal structures within mammalian cells. This user-friendly technique can be set up with commercially available imaging systems and does not require specialized equipment inaccessible to standard cell biology laboratories.

Kızılötesi Lazer Destekli Mikropatterning ile Hücre Geometrisinin Kontrolü

Micropatterning is an established technique in the cell biology community used to study connections between the morphology and function of cellular ...

Pattern Generation for Micropattern Traction Microscopy

Micropattern traction microscopy allows control of the shape of single cells and cell clusters. Furthermore, the ability to pattern at the micrometer length scale allows the use of these patterned contact zones for the measurement of traction forces, as each micropatterned dot allows for the formation of a single focal adhesion that then deforms the soft, underlying hydrogel. This approach has been used for a wide range of cell types, including endothelial cells, smooth muscle cells, fibroblasts, platelets, and epithelial cells. 
This review describes the evolution of techniques that allow the printing of extracellular matrix proteins onto polyacrylamide hydrogels in a regular array of dots of prespecified size and spacing. As micrometer-scale patterns are difficult to directly print onto soft substrates, patterns are first generated on rigid glass coverslips that are then used to transfer the pattern to the hydrogel during gelation. First, the original microcontact printing approach to generate arrays of small dots on the coverslip is described. A second step that removes most of the pattern to leave islands of small dots is required to control the shapes of cells and cell clusters on such arrays of patterned dots. 
Next, an evolution of this approach that allows for the generation of islands of dots using a single subtractive patterning step is described. This approach is greatly simplified for the user but has the disadvantage of a decreased lifetime for the master mold needed to make the patterns. Finally, the computational approaches that have been developed for the analysis of images of displaced dots and subsequent cell-generated traction fields are described, and updated versions of these analysis packages are provided.

We describe improvements to a standard method for measuring cellular traction forces, based on microcontact printing with a single subtractive patterning step of dot arrays of extracellular matrix proteins on soft hydrogels. This method allows for simpler and more consistent fabrication of island patterns, essential for controlling cell cluster shape.

Mikrodesen Traksiyon Mikroskobu için Desen Oluşturma

Micropattern traction microscopy allows control of the shape of single cells and cell clusters. Furthermore, the ability to pattern at the micrometer ...