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

Funding for this research was provided by the New Jersey Commission on Spinal Cord Research (NJCSCR) (to FHK), grant CSCR14IRG005 (to BLF), NIH grant R15NS087501 (to CHC), and the F.M. Kirby Foundation (to ETA).

NOTE: Please consult all relevant material safety data sheets (MSDS) before use. Some of the chemicals used in this protocol are toxic and carcinogenic. Please use all appropriate safety practices (fume hood, glovebox) and personal protective equipment (safety glasses, gloves, lab coat, full length pants, closed-toe shoes) when using toxic or acid/base materials.
1. Fabrication of Master Molds for Soft Lithography using Photolithography
<ol>
	<li>Draw the layout of the microchannel using a c...

<ol>
	<li>Kane, R. S., Takayama, S., Ostuni, E., Ingber, D. E., Whitesides, G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Patterning+proteins+and+cells+using+soft+lithography.">Patterning proteins and cells using soft lithography.</a> Biomaterials. 20 (23-24), 2363-2376 (1999).</li><li>Lin, R. Z., Ho, C. T., Liu, C. H., Chang, H. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dielectrophoresis+based-cell+patterning+for+tissue+engineering.">Dielectrophoresis based-cell patterning for tissue engineering.</a> Biotechnol J. 1 (9), 949-957 (2006).</li><li>Veiseh, M., Zareie, M. H., Zhang, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Highly+Selective+Protein+Patterning+on+Gold-Silicon+Substrates+for+Biosensor+Applications.">Highly Selective Protein Patterning on Gold-Silicon Substrates for Biosensor Applications.</a> Langmuir. 18 (17), 6671-6678 (2002).</li><li>Kung, F., Wang, J., Perez-Castillejos, R., 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=Position+along+the+nasal/temporal+plane+affects+synaptic+development+by+adult+photoreceptors,+revealed+by+micropatterning.">Position along the nasal/temporal plane affects synaptic development by adult photoreceptors, revealed by micropatterning.</a> Integr Biol. 7 (3), 313-323 (2015).</li><li>Dickinson, L. E., Lutgebaucks, C., Lewis, D. M., Gerecht, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Patterning+microscale+extracellular+matrices+to+study+endothelial+and+cancer+cell+interactions+in+vitro.">Patterning microscale extracellular matrices to study endothelial and cancer cell interactions in vitro.</a> Lab Chip. 12 (21), 4244-4248 (2012).</li><li>Khademhosseini, 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=Co-culture+of+human+embryonic+stem+cells+with+murine+embryonic+fibroblasts+on+microwell-patterned+substrates.">Co-culture of human embryonic stem cells with murine embryonic fibroblasts on microwell-patterned substrates.</a> Biomaterials. 27 (36), 5968-5977 (2006).</li><li>Bogdanowicz, D. R., Lu, H. 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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=Efficient+Immobilization+and+Patterning+of+Biomolecules+on+Poly(ethylene+terephthalate)+Films+Functionalized+by+Ion+Irradiation+for+Biosensor+Applications.">Efficient Immobilization and Patterning of Biomolecules on Poly(ethylene terephthalate) Films Functionalized by Ion Irradiation for Biosensor Applications.</a> ACS Appl Mater Interf. 3 (7), 2235-2239 (2011).</li><li>Clark, P., Britland, S., Connolly, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Growth+cone+guidance+and+neuron+morphology+on+micropatterned+laminin+surfaces.">Growth cone guidance and neuron morphology on micropatterned laminin surfaces.</a> J Cell Sci. 105 (1), 203-212 (1993).</li><li>Th&#233;ry, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Micropatterning+as+a+tool+to+decipher+cell+morphogenesis+and+functions.">Micropatterning as a tool to decipher cell morphogenesis and functions.</a> J Cell Sci. 123 (24), 4201-4213 (2010).</li><li>Douvas, 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=Biocompatible+photolithographic+process+for+the+patterning+of+biomolecules.">Biocompatible photolithographic process for the patterning of biomolecules.</a> Biosens Bioelectron. 17 (4), 269-278 (2002).</li><li>Alom, R. S., Chen, C. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microcontact+printing:+A+tool+to+pattern.">Microcontact printing: A tool to pattern.</a> Soft Matter. 3 (2), 168-177 (2007).</li><li>Ess&#246;, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modifying+Polydimethylsiloxane+(PDMS)+surfaces.">Modifying Polydimethylsiloxane (PDMS) surfaces.</a> Institutionen f&#246;r biologi och kemiteknik. , (2007).</li><li>Zhou, J., Ellis, A. V., Voelcker, N. 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N., Mrksich, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dynamic+interfaces+between+cells+and+surfaces:+electroactive+substrates+that+sequentially+release+and+attach+cells.">Dynamic interfaces between cells and surfaces: electroactive substrates that sequentially release and attach cells.</a> J Am Chem Soc. 125 (49), 14994-14995 (2003).</li><li>Bhatia, S. N., Toner, M., Tompkins, R. G., Yarmush, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Selective+adhesion+of+hepatocytes+on+patterned+surfaces.">Selective adhesion of hepatocytes on patterned surfaces.</a> Ann N Y Acad Sci. 745, 187-209 (1994).</li><li>Song, E., Kim, S. Y., Chun, T., Byun, H. -. J., Lee, Y. 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S., Lee, K. -. C., Kwon, T. H., Lee, S. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Micro-channel+filling+flow+considering+surface+tension+effect.">Micro-channel filling flow considering surface tension effect.</a> J of Micromech Microeng. 12 (3), 236 (2002).</li><li>Kim, E., Xia, Y., Whitesides, G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Micromolding+in+Capillaries:+Applications+in+Materials+Science.">Micromolding in Capillaries: Applications in Materials Science.</a> J Am Chem Soc. 118 (24), 5722-5731 (1996).</li><li>Kim, E., Xia, Y. N., Whitesides, G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polymer+Microstructures+Formed+by+Molding+in+Capillaries.">Polymer Microstructures Formed by Molding in Capillaries.</a> Nature. 376 (6541), 581-584 (1995).</li><li>Jeon, N. L., Choi, I. S., Xu, B., Whitesides, G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Large-area+patterning+by+vacuum-assisted+micromolding.">Large-area patterning by vacuum-assisted micromolding.</a> Adv Mater. 11 (11), 946 (1999).</li><li>Shrirao, A. 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=System+and+method+for+novel+microfluidic+device.">System and method for novel microfluidic device.</a> US patent. , (2010).</li><li>Merkel, T. C., Bondar, V. I., Nagai, K., Freeman, B. 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>

While conventional photolithography is a well-established technique for the creation of molds for soft lithography, the equipment, materials, and skills necessary to use conventional photolithography are not readily available to most laboratories. For laboratories without access to these resources, we have presented adhesive tape fabrication as a method of creating molds with relatively simple features for microfluidic devices. This method allows any laboratory to create and utilize microfluidic devices for research purp...

In tissue engineering and biosensing, the ability to control the spatial organization of proteins and cells on a &#181;m scale, has become increasingly important over the last four decades1,2,3. Precise spatial organization of proteins and cells has allowed researchers to examine the interaction between cells and substrates containing similar or different types of cells, to guide cell growth, and to immobilize biomolecules for the fabrication of biosensors4,5,6,7,8,9.
Current methods of patterning proteins include photopatterning and microcontact printing. Photopatterning utilizes light sensitive material which is crosslinked upon exposure to ultra violet (UV) light. UV light directed at a photomask (consisting of transparent areas with darker regions to prevent UV light transmission) causes crosslinking in specific regions which can then be used for subsequent attachment of biomaterials or cells10,11. While this scheme is very accurate and allows for precise control of the topography of the culture surface, it is limited to UV-sensitive biomolecules that can be patterned by UV radiation12. Microcontact printing is another popular method of patterning specific proteins13,14. In this method, a poly-dimethyl siloxane (PDMS) stamp is treated with a variety of surface modification reagents before being soaked in a solution of the chosen biomolecular substrate. It is then gently pressed onto a glass coverslip or other surface thus &#34;stamping&#34; the biomolecule onto the culture surface. However, stamping is limited to the type of material that can be transferred as well as the wettability of biomolecules to the surface of the PDMS stamp15.
Direct patterning of cells can be more difficult and relies on complex methods such as switchable substrates, stencil based methods, or patterning with specific cell adhesion molecules16,17. These methods are limited in their ability to pattern cells due to the lack of compatible cell adhesion substrates, incompatibility of the process to work with sensitive biological cells and constraints, inconsistency in reproducing the patterning, and complexity of the procedure. For example, with switchable substrates, custom substrates need to be designed for every cell type, to switch their adherence to specific cell types without degradation upon exposure to the UV light and heat used in process17,18,19,20. Stencil based patterning methods are versatile in their ability to pattern cells; however, it is difficult to manufacture PDMS stencils at the appropriate thicknesses for use16,21. Direct injection of cells into PDMS microfluidic channels have some advantages such as: 1) ease in fabrication of microfluidic channels and 2) suitability for many different cells and substrates. However, the prevalent issue of air bubble capture during the injection process due to the hydrophobicity of PDMS without the use of plasma cleaning, or other methods to decrease air bubbles, makes it difficult to consistently create patterned cells on glass or plastic surfaces21.
This work expands upon capillary micromolding22,23,24,25,26 and reports a method to inject protein and cell suspensions into microchannels. The method used here demonstrates the patterning of substrates and both direct and indirect patterning of specific cell types. This technique overcomes the high hydrophobicity of PDMS and eliminates the presence of bubbles during injection of either substrates or cells by taking advantage of the gas permeability of PDMS27. This paper demonstrates the use of the technique with several different substrates and cell types. The article also highlights the fabrication of molds for soft lithography using conventional photolithography as well as a simple and low-cost adhesive tape method useful in resource limited settings28,29.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<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 &#181;L aliquots and diluted to 20 &#181;g/&#181;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.

This method allows the patterning of proteins and indirect patterning of cells using dead-end microfluidic channels with dimensions as small as 10 &#181;m and equipment available in almost all biological laboratories once the master mold is made. This technique can be utilized with PDMS microfluidic channels created using traditional soft photolithography, or with PDMS microfluidic channels created with adhesive tape fabrication (Figure 1)28,<...

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.

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

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Bioengineering

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Visualization of Cortex Organization and Dynamics in Microorganisms, using Total Internal Reflection Fluorescence Microscopy

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A Versatile Automated Platform for Micro-scale Cell Stimulation Experiments

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A Microfluidic Chip for the Versatile Chemical Analysis of Single Cells

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Cell Patterning on Photolithographically Defined 
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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 ...

Rapid Subtractive Patterning of Live Cell Layers with a Microfluidic Probe

The microfluidic probe (MFP) facilitates performing local chemistry on biological substrates by confining nanoliter volumes of liquids. Using one ...

Light-mediated Formation and Patterning of Hydrogels for Cell Culture Applications

Click chemistries have been investigated for use in numerous biomaterials applications, including drug delivery, tissue engineering, and cell culture. In ...

Patterning Bioactive Proteins or Peptides on Hydrogel Using Photochemistry for Biological Applications

There are many biological stimuli that can influence cell behavior and stem cell differentiation. General cell culture approaches rely on soluble factors ...

DNA Nanotubes as a Versatile Tool to Study Semiflexible Polymers

Mechanical properties of complex, polymer-based soft matter, such as cells or biopolymer networks, can be understood in neither the classical frame of ...