The authors thank Professor Tang K. Tang, Institute of Biomedical Sciences, Academia Sinica, for his assistance in providing mouse neural stem and progenitor cells (mNPCs). The authors also thank Professor Tang K. Tang and Ms. Ying-Shan Lee, for their valuable discussion on the differentiation of mNPCs.

1. Design and fabrication of the MOE chip
<ol>
	<li>Draw patterns for individual polymethyl methacrylate (PMMA) layers and the double-sided tape using appropriate software (Figure 1A, Table of Materials). Cut both the PMMA sheets and the double-sided tape with a CO2 laser machine scriber (Figure 1B).
	<ol>
		<li>Switch on the CO2 laser scriber and connect it to a personal computer. Open the designed pattern file using the...

<ol>
	<li>Chang, H. F., Lee, Y. S., Tang, T. K., Cheng, J. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pulsed+DC+electric+field-induced+differentiation+of+cortical+neural+precursor+cells.">Pulsed DC electric field-induced differentiation of cortical neural precursor cells.</a> PLoS One. 11 (6), e0158133 (2016).</li><li>Li, S., Li, H., Wang, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Orientation+of+spiral+ganglion+neurite+extension+in+electrical+fields+of+charge-balanced+biphasic+pulses+and+direct+current+in+vitro.">Orientation of spiral ganglion neurite extension in electrical fields of charge-balanced biphasic pulses and direct current in vitro.</a> Hearing research. 267 (1-2), 111-118 (2010).</li><li>Rajnicek, A. M., Robinson, K. R., McCaig, C. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+direction+of+neurite+growth+in+a+weak+DC+electric+field+depends+on+the+substratum:+contributions+of+adhesivity+and+net+surface+charge.">The direction of neurite growth in a weak DC electric field depends on the substratum: contributions of adhesivity and net surface charge.</a> Developmental biology. 203 (2), 412-423 (1998).</li><li>Kim, Y. 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=Differential+regulation+of+proliferation+and+differentiation+in+neural+precursor+cells+by+the+Jak+pathway.">Differential regulation of proliferation and differentiation in neural precursor cells by the Jak pathway.</a> Stem Cells. 28 (10), 1816-1828 (2010).</li><li>Cunha, F., Rajnicek, A. M., McCaig, C. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrical+stimulation+directs+migration,+enhances+and+orients+cell+division+and+upregulates+the+chemokine+receptors+CXCR4+and+CXCR2+in+endothelial+cells.">Electrical stimulation directs migration, enhances and orients cell division and upregulates the chemokine receptors CXCR4 and CXCR2 in endothelial cells.</a> Journal of Vascular Research. 56 (1), 39-53 (2019).</li><li>Chang, H. F., Cheng, H. T., Chen, H. Y., Yeung, W. K., Cheng, J. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Doxycycline+inhibits+electric+field-induced+migration+of+non-small+cell+lung+cancer+(NSCLC)+cells.">Doxycycline inhibits electric field-induced migration of non-small cell lung cancer (NSCLC) cells.</a> Scientific Reports. 9 (1), 8094 (2019).</li><li>Tsai, H. F., Peng, S. W., Wu, C. Y., Chang, H. F., Cheng, J. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrotaxis+of+oral+squamous+cell+carcinoma+cells+in+a+multiple-electric-field+chip+with+uniform+flow+field.">Electrotaxis of oral squamous cell carcinoma cells in a multiple-electric-field chip with uniform flow field.</a> Biomicrofluidics. 6 (3), 34116 (2012).</li><li>Huang, C. W., Cheng, J. Y., Yen, M. H., Young, T. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrotaxis+of+lung+cancer+cells+in+a+multiple-electric-field+chip.">Electrotaxis of lung cancer cells in a multiple-electric-field chip.</a> Biosensors and Bioelectronics. 24 (12), 3510-3516 (2009).</li><li>Jing, W., 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=Study+of+electrical+stimulation+with+different+electric-field+intensities+in+the+regulation+of+the+differentiation+of+PC12+cells.">Study of electrical stimulation with different electric-field intensities in the regulation of the differentiation of PC12 cells.</a> American Chemical Society Chemical Neuroscience. 10 (1), 348-357 (2019).</li><li>Guo, W., 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-powered+electrical+stimulation+for+enhancing+neural+differentiation+of+mesenchymal+stem+cells+on+graphene-poly(3,4-ethylenedioxythiophene)+hybrid+microfibers.">Self-powered electrical stimulation for enhancing neural differentiation of mesenchymal stem cells on graphene-poly(3,4-ethylenedioxythiophene) hybrid microfibers.</a> American Chemical Society Nano. 10 (5), 5086-5095 (2016).</li><li>Manabe, M., Mie, M., Yanagida, Y., Aizawa, M., Kobatake, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Combined+effect+of+electrical+stimulation+and+cisplatin+in+HeLa+cell+death.">Combined effect of electrical stimulation and cisplatin in HeLa cell death.</a> Biotechnology and Bioengineering. 86 (6), 661-666 (2004).</li><li>Liu, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Protective+effect+of+moderate+exogenous+electric+field+stimulation+on+activating+netrin-1/DCC+expression+against+mechanical+stretch-induced+injury+in+spinal+cord+neurons.">Protective effect of moderate exogenous electric field stimulation on activating netrin-1/DCC expression against mechanical stretch-induced injury in spinal cord neurons.</a> Neurotoxicity Research. 34 (2), 285-294 (2018).</li><li>Haan, N., Song, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Therapeutic+application+of+electric+fields+in+the+injured+nervous+system.">Therapeutic application of electric fields in the injured nervous system.</a> Advances in Wound Care. 3 (2), 156-165 (2014).</li><li>Ariza, C. 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=The+influence+of+electric+fields+on+hippocampal+neural+progenitor+cells.">The influence of electric fields on hippocampal neural progenitor cells.</a> Stem Cell Reviews and Reports. 6 (4), 585-600 (2010).</li><li>Huang, C. W., 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=Gene+expression+of+human+lung+cancer+cell+line+CL1-5+in+response+to+a+direct+current+electric+field.">Gene expression of human lung cancer cell line CL1-5 in response to a direct current electric field.</a> PLoS One. 6 (10), e25928 (2011).</li><li>Sun, Y. S., Peng, S. W., Lin, K. H., Cheng, J. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrotaxis+of+lung+cancer+cells+in+ordered+three-dimensional+scaffolds.">Electrotaxis of lung cancer cells in ordered three-dimensional scaffolds.</a> Biomicrofluidics. 6 (1), 14102-14114 (2012).</li><li>Hou, H. S., Chang, H. F., Cheng, J. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrotaxis+studies+of+lung+cancer+cells+using+a+multichannel+dual-electric-field+microfluidic+chip.">Electrotaxis studies of lung cancer cells using a multichannel dual-electric-field microfluidic chip.</a> Journal of Visualized Experiments. 106, e53340 (2015).</li><li>Cheng, J. Y., Yen, M. H., Hsu, W. C., Jhang, J. H., Young, T. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=ITO+patterning+by+a+low+power+Q-switched+green+laser+and+its+use+in+the+fabrication+of+a+transparent+flow+meter.">ITO patterning by a low power Q-switched green laser and its use in the fabrication of a transparent flow meter.</a> Journal of Micromechanics and Microengineering. 17 (11), 2316-2323 (2007).</li><li>Cheng, J. Y., Yen, M. H., Kuo, C. T., Young, T. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+transparent+cell-culture+microchamber+with+a+variably+controlled+concentration+gradient+generator+and+flow+field+rectifier.">A transparent cell-culture microchamber with a variably controlled concentration gradient generator and flow field rectifier.</a> Biomicrofluidics. 2 (2), 24105 (2008).</li><li>Fuhr, G., Shirley, S. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+handling+and+characterization+using+micron+and+submicron+electrode+arrays:+state+of+the+art+and+perspectives+of+semiconductor+microtools.">Cell handling and characterization using micron and submicron electrode arrays: state of the art and perspectives of semiconductor microtools.</a> Journal of Micromechanics and Microengineering. 5 (2), 77-85 (1995).</li><li>AChang, K. 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=Biphasic+electrical+currents+stimulation+promotes+both+proliferation+and+differentiation+of+fetal+neural+stem+cells.">Biphasic electrical currents stimulation promotes both proliferation and differentiation of fetal neural stem cells.</a> PLoS One. 6 (4), e18738 (2011).</li><li>Lim, J. H., McCullen, S. D., Piedrahita, J. A., Loboa, E. G., Olby, N. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Alternating+current+electric+fields+of+varying+frequencies:+effects+on+proliferation+and+differentiation+of+porcine+neural+progenitor+cells.">Alternating current electric fields of varying frequencies: effects on proliferation and differentiation of porcine neural progenitor cells.</a> Cell Reprogram. 15 (5), 405-412 (2013).</li></ol>

During the fabrication of the MOE chip, the adaptors are attached to the Layer 1 of the MOE chip with fast-acting cyanoacrylate glue. The glue is applied to 4 corners of the adaptors, and then pressure is applied evenly over the adaptors. Excess amount of glue must be avoided to ensure complete polymerization of the glue. Moreover, the completed MOE chip assembly is incubated in a vacuum chamber. This step helps to remove the bubbles between the PMMA layer, the double-sided tape, and the cover glass.
<p class="jove_c...

Neural precursor cells (NPCs, also known as neural stem and progenitor cells) can be as a promising candidate for neurodegenerative therapeutic strategy1. The undifferentiated NPCs have self-renewal capacity, multi-potency, and proliferative ability2,3. A previous study has reported that the extracellular matrix and molecular mediators regulate differentiation of NPC. The epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) promote NPC proliferation, thus maintaining the undifferentiated state4.
Previous studies have reported that electrical stimulation can regulate cell physiologic activities such as division5, migration6,7,8, differentiation1,9,10, and cell death11. Electric fields (EFs) play vital roles in the development and regeneration of the central nervous system development12,13,14. From 2009 to 2019, this laboratory has investigated cellular responses to the application of EF in the microfluidic system1,6,7,8,15,16,17. A multichannel, optically transparent, electrotactic (MOE) chip was designed to be suitable for immunofluorescence staining for confocal microscopy. The chip had high optical transparency and good durability and allowed the simultaneous conduct of three independent stimulation experiments and several immunostained conditions in a single study. The microfluidic system is beneficial in simplifying the overall experimental setup and, in turn, the reagent and sample consumption. This paper describes the development of a microfluidic cell culture system that was used for a long-term cell differentiation study.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>1 mm PMMA substrates (Layers 1-3)</td>
			<td>BHT</td>
			<td>K2R20</td>
			<td>Polymethyl methacrylate (PMMA), http://www.bothharvest.com/zh-tw/product-421076/Optical-PMMA-Non-Coated-BHT-K2Rxx-xx=-thickness-choices.html</td>
		</tr>
		<tr>
			<td>15 mL plastic tube</td>
			<td>Protech Technology Enterprise Co., Ltd</td>
			<td>CT-15-PL-TW</td>
			<td>Conical bottomed tube with cap, assembled, presterilized</td>
		</tr>
		<tr>
			<td>3 mL syringe</td>
			<td>TERUMO</td>
			<td>DVR-3413</td>
			<td>3 mL oral syringes, without needle</td>
		</tr>
		<tr>
			<td>3 mm optical grade PMMA (Layer 5)</td>
			<td>CHI MEI Corporation</td>
			<td>ACRYPOLY PMMA Sheet</td>
			<td>Optical grade PMMA</td>
		</tr>
		<tr>
			<td>3-way stopcock</td>
			<td>NIPRO</td>
			<td>NCN-3L</td>
			<td>Sterile disposable 3-way stopcock</td>
		</tr>
		<tr>
			<td>5 mL syringe</td>
			<td>TERUMO</td>
			<td>DVR-3410</td>
			<td>5 mL oral syringes, without needle</td>
		</tr>
		<tr>
			<td>Adaptor</td>
			<td>Dong Zhong Co., Ltd.</td>
			<td>Customized</td>
			<td>PMMA adaptor</td>
		</tr>
		<tr>
			<td>Agarose</td>
			<td>Sigma-Aldrich</td>
			<td>A9414</td>
			<td>Agarose, low gelling temperature</td>
		</tr>
		<tr>
			<td>Amplifier</td>
			<td>A.A. Lab Systems Ltd</td>
			<td>A-304</td>
			<td>High voltage amplifier</td>
		</tr>
		<tr>
			<td>AutoCAD software</td>
			<td>Autodesk</td>
			<td>Educational Version</td>
			<td>Drafting</td>
		</tr>
		<tr>
			<td>B-27 supplement</td>
			<td>Gibco</td>
			<td>12587-010</td>
			<td>B-27 supplement (50x), minus vitamin A</td>
		</tr>
		<tr>
			<td>Basic fibroblast growth factor (bFGF)&#160;</td>
			<td>Peprotech</td>
			<td>AF-100-18B</td>
			<td>Also called recombinant human FGF-basic</td>
		</tr>
		<tr>
			<td>Black rubber bung</td>
			<td>TERUMO</td>
			<td>DVR-3413</td>
			<td>From 3 mL oral syringes, without needle</td>
		</tr>
		<tr>
			<td>Bovine serum albumin (BSA)</td>
			<td>Sigma-Aldrich</td>
			<td>B4287</td>
			<td>Blocking reagent&#160;</td>
		</tr>
		<tr>
			<td>Centrifuge</td>
			<td>HSIANGTAI</td>
			<td>CV2060</td>
			<td>Centrifuge</td>
		</tr>
		<tr>
			<td>CO2 laser scriber</td>
			<td>Laser Tools and Technics Corp.&#160;</td>
			<td>ILS-II</td>
			<td>Purchased from http://www.lttcorp.com/index.htm</td>
		</tr>
		<tr>
			<td>Cone connector</td>
			<td>IDEX Health &#38; Science</td>
			<td>F-120X</td>
			<td>One-piece fingertight 10-32 coned, for 1/16&#34; OD natural</td>
		</tr>
		<tr>
			<td>Cone-Luer adaptor</td>
			<td>IDEX Health &#38; Science</td>
			<td>P-659</td>
			<td>Luer Adapter 10-32 Female to Female Luer, PEEK</td>
		</tr>
		<tr>
			<td>Confocal fluorescence microscope</td>
			<td>Leica Microsystems</td>
			<td>TCS SP5</td>
			<td>Leica TCS SP5 user manual, http://www3.unifr.ch/bioimage/wp-content/uploads/2013/10/User-Manual_TCS_SP5_V02_EN.pdf</td>
		</tr>
		<tr>
			<td>Digital camera</td>
			<td>OLYMPUS</td>
			<td>E-330</td>
			<td>Automatic time-lapse image acquisition</td>
		</tr>
		<tr>
			<td>Digital oscilloscope</td>
			<td>Tektronix</td>
			<td>TDS2024</td>
			<td>Measure voltage or current signals over time in an electronic circuit or component to display amplitude and frequency.</td>
		</tr>
		<tr>
			<td>Double-sided tape</td>
			<td>3M&#160;</td>
			<td>PET 8018</td>
			<td>Purchased from http://en.thd.com.tw/</td>
		</tr>
		<tr>
			<td>Dulbecco&#8217;s modified Eagle&#8217;s medium/Ham&#39;s nutrient mixture F-12 (DMEM/F12)</td>
			<td>Gibco</td>
			<td>12400024</td>
			<td>DMEM/F-12, powder, HEPES</td>
		</tr>
		<tr>
			<td>Dulbecco&#39;s phosphate-buffered saline (DPBS)</td>
			<td>Gibco</td>
			<td>21600010</td>
			<td>DPBS, powder, no calcium, no magnesium</td>
		</tr>
		<tr>
			<td>EF multiplexer</td>
			<td>Asiatic Sky Co., Ltd.</td>
			<td>Customized</td>
			<td>Monitor and control the electric current in individual channels</td>
		</tr>
		<tr>
			<td>Epidermal growth factor (EGF)</td>
			<td>Peprotech</td>
			<td>AF-100-15</td>
			<td>Also called recombinant human EGF</td>
		</tr>
		<tr>
			<td>Fast-acting cyanoacrylate glue</td>
			<td>3M&#160;</td>
			<td>7004T</td>
			<td>Strength instant adhesive (liquid)</td>
		</tr>
		<tr>
			<td>Flat bottom connector</td>
			<td>IDEX Health &#38; Science</td>
			<td>P-206</td>
			<td>Flangeless male nut Delrin, 1/4-28 flat-bottom, for 1/16&#34; OD blue</td>
		</tr>
		<tr>
			<td>Function generator</td>
			<td>Agilent Technologies</td>
			<td>33120A</td>
			<td>High-performance 15 MHz synthesized&#160;function generator&#160;with built-in arbitrary waveform capability</td>
		</tr>
		<tr>
			<td>Goat anti-mouse IgG H&#38;L (Alexa Fluor 488)</td>
			<td>Abcam</td>
			<td>ab150117</td>
			<td>Goat anti-mouse IgG H&#38;L (Alexa Fluor 488) preadsorbed</td>
		</tr>
		<tr>
			<td>Goat anti-rabbit IgG H&#38;L (Alexa Fluor 555)</td>
			<td>Abcam</td>
			<td>ab150086</td>
			<td>Goat polyclonal secondary antibody to rabbit IgG - H&#38;L (Alexa Fluor 555), preadsorbed</td>
		</tr>
		<tr>
			<td>Hoechst 33342</td>
			<td>Invitrogen</td>
			<td>H3570</td>
			<td>Nuclear staining</td>
		</tr>
		<tr>
			<td>ImageJ software</td>
			<td>National Institutes of Health</td>
			<td>1.48v</td>
			<td>Analyze the fluorescent images&#160;</td>
		</tr>
		<tr>
			<td>Indium&#8211;tin&#8211;oxide (ITO) glass</td>
			<td>Merck</td>
			<td>300739</td>
			<td>For ITO heater</td>
		</tr>
		<tr>
			<td>Inverted phase contrast microscope</td>
			<td>OLYMPUS</td>
			<td>CKX41</td>
			<td>For cell morphology observation</td>
		</tr>
		<tr>
			<td>K-type thermocouple</td>
			<td>Tecpel</td>
			<td>TPK-02A</td>
			<td>Temperature&#160;thermocouples</td>
		</tr>
		<tr>
			<td>Luer adapter</td>
			<td>IDEX Health &#38; Science</td>
			<td>P618-01</td>
			<td>Luer adapter female Luer to 1/4-28 male polypropylene</td>
		</tr>
		<tr>
			<td>Luer lock syringe</td>
			<td>TERUMO</td>
			<td>DVR-3413</td>
			<td>For agar salt bridges</td>
		</tr>
		<tr>
			<td>Mouse anti-GFAP</td>
			<td>eBioscience</td>
			<td>14-9892</td>
			<td>Astrocytes marker</td>
		</tr>
		<tr>
			<td>Oligodendrocyte &#160;marker&#160; O4&#160; antibody</td>
			<td>R&#38;D Systems</td>
			<td>MAB1326</td>
			<td>Oligodendrocytes marker</td>
		</tr>
		<tr>
			<td>Paraformaldehyde (PFA)</td>
			<td>Sigma-Aldrich</td>
			<td>P6148</td>
			<td>Fixing&#160;agent</td>
		</tr>
		<tr>
			<td>Phosphate buffered saline (PBS)</td>
			<td>Basic Life</td>
			<td>BL2651</td>
			<td>Washing solution</td>
		</tr>
		<tr>
			<td>Poly-L-Lysine (PLL)</td>
			<td>SIGMA</td>
			<td>P4707</td>
			<td>Coating solution</td>
		</tr>
		<tr>
			<td>Precision cover glasses thickness No. 1.5H</td>
			<td>MARIENFELD</td>
			<td>107242</td>
			<td>https://www.marienfeld-superior.com/precision-cover-glasses-thickness-no-1-5h-tol-5-m.html</td>
		</tr>
		<tr>
			<td>Programmable X-Y-Z motorised stage</td>
			<td>Tanlian Inc</td>
			<td>Customized</td>
			<td>Purchased from http://www.tanlian.tw/ndex.files/motort.htm</td>
		</tr>
		<tr>
			<td>Proportional&#8211;integral&#8211;derivative (PID) controller</td>
			<td>Toho Electronics</td>
			<td>TTM-J4-R-AB</td>
			<td>Temperature controller&#160;</td>
		</tr>
		<tr>
			<td>PTFE tube</td>
			<td>Professional Plastics Inc. Taiwan Branch</td>
			<td>Outer diameter 1/16 Inches</td>
			<td>White translucent PTFE tubing</td>
		</tr>
		<tr>
			<td>Rabbit anti-Tuj1</td>
			<td>Abcam</td>
			<td>ab18207</td>
			<td>Neuron marker</td>
		</tr>
		<tr>
			<td>Syringe pump</td>
			<td>New Era Systems Inc</td>
			<td>NE-1000</td>
			<td>NE-1000 programmable single syringe pump</td>
		</tr>
		<tr>
			<td>TFD4 detergent</td>
			<td>FRANKLAB</td>
			<td>TFD4</td>
			<td>Cover glass cleaner</td>
		</tr>
		<tr>
			<td>Thermal bonder</td>
			<td>Kuan-MIN Tech Co.</td>
			<td>Customized</td>
			<td>Purchased from http://kmtco.com.tw/</td>
		</tr>
		<tr>
			<td>Triton X-100</td>
			<td>Sigma-Aldrich</td>
			<td>T8787</td>
			<td>Permeabilized solution</td>
		</tr>
		<tr>
			<td>Ultrasonic cleaner</td>
			<td>LEO</td>
			<td>LEO-300S</td>
			<td>Ultrasonic steri-cleaner</td>
		</tr>
		<tr>
			<td>Vacuum chamber</td>
			<td>DENG YNG INSTRUMENTS CO., Ltd.</td>
			<td>DOV-30</td>
			<td>Vacuum drying oven</td>
		</tr>
		<tr>
			<td>White fingertight plug</td>
			<td>IDEX Health &#38; Science</td>
			<td>P-316</td>
			<td>1/4-28 Flat-Bottom, https://www.idex-hs.com/store/fluidics/fluidic-connections/plug-teflonr-pfa-1-4-28-flat-bottom.html</td>
		</tr>
	</tbody>
</table>

electric-field-induced neural precursor cell differentiation in microfluidic devices

Physiological electric fields (EF) play vital roles in cell migration, differentiation, division, and death. This paper describes a microfluidic cell culture system that was used for a long-term cell differentiation study using microscopy. The microfluidic system consists of the following major components: an optically transparent electrotactic chip, a transparent indium-tin-oxide (ITO) heater, a culture media-filling pump, an electrical power supply, a high-frequency power amplifier, an EF multiplexer, a programmable X-Y-Z motorized stage, and an inverted phase-contrast microscope equipped with a digital camera. The microfluidic system is beneficial in simplifying the overall experimental setup and, in turn, the reagent and sample consumption. This work involves the differentiation of neural stem and progenitor cells (NPCs) induced by direct current (DC) pulse stimulation. In the stem cell maintenance medium, the mouse NPCs (mNPCs) differentiated into neurons, astrocytes, and oligodendrocytes after the DC pulse stimulation. The results suggest that simple DC pulse treatment could control the fate of mNPCs and could be used to develop therapeutic strategies for nervous system disorders. The system can be used for cell culture in multiple channels, for long-term EF stimulation, for cell morphological observation, and for automatic time-lapse image acquisition. This microfluidic system not only shortens the required experimental time, but also increases the accuracy of control on the microenvironment.

The detailed configuration of the MOE chip is shown in Figure 1. The microfluidic chip provides a beneficial approach for reducing the experimental setup size, sample volume, and reagent volume. The MOE chip was designed to perform three independent EF stimulation experiments and several immunostaining conditions simultaneously in a single study (Figure 3). In addition, the MOE chip, which has a high optical transparency is suita...

Watch this Scientific Journal Video about Electric-Field-Induced Neural Precursor Cell Differentiation in Microfluidic Devices at JoVE.com

Electric-Field-Induced Neural Precursor Cell Differentiation in Microfluidic Devices

In this study, we present a protocol for the differentiation of neural stem and progenitor cells (NPCs) solely induced by direct current (DC) pulse stimulation in a microfluidic system.

Physiological electric fields (EF) play vital roles in cell migration, differentiation, division, and death. This paper describes a microfluidic cell ...

This study presents a protocol for the differentiation of neural precursor cells solely induced by direct current pulse stimulation in a microfluidic system. This technique provides a beneficial approach for reducing the experimental setup time, sample volume, and reagent volume. Furthermore, the MOE chip is suitable for confocal microscopy observations.The simple direct current pulse treatment can control mouse neural precursor cells'fate and could be used to develop therapeutic strategies for nervous system disorders. To begin, draw patterns for individual PMMA layers and the double-sided tape using appropriate software. Switch on the carbon dioxide laser scriber and connect it to a personal computer.Open the designed pattern file using the software. Place the PMMA sheets or double-sided tape on the platform of the laser scriber, then focus the laser onto the surface of the PMMA sheets or the double-sided tape using the auto-focus tool. Select the laser scriber as the printer, then use the laser scriber to start the direct ablation on the PMMA sheet or double-sided tape.Remove the protective film from the PMMA sheets and clean the surface using nitrogen gas. For bonding together multiple layers of PMMA sheets, stack three pieces of one millimeter PMMA sheets and bond them under a pressure of five kilograms per square centimeter in a thermal bonder for 30 minutes at 110 degrees Celsius to form the flow or electrical stimulation channel assembly. Adhere 12 pieces of adapters to the individual openings in layer one of the MOE chip assembly with fast acting cyanoacrylate glue.Disinfect the one millimeter PMMA substrates, the double-sided tape, and the three millimeter optical grade PMMA using ultraviolet irradiation for 30 minutes before assembling the chip. Adhere the one millimeter PMMA substrates on the three millimeter optical grade PMMA with the double-sided tape to complete the PMMA assembly. Adhere the cleaned coverglass to the PMMA assembly with the double-sided tape.Seal the openings of the agar bridge adapters with white finger-tight plugs. Connect the flat bottom connector to the MOE chip assembly via the medium inlet and outlet adapters, then connect the cone Luer adapter to the three-way stopcocks. Add two milliliters of 0.01%PLL solution using a three milliliter syringe that connects to the three-way stopcock of the medium inlet, and connect an empty three milliliter syringe to the three-way stopcock of the medium outlet.Fill the cell culture regions with the PLL solution, and slowly pump the coating solution back and forth. Close the two three-way stopcocks to seal the solution inside the culture regions. Incubate the MOE chip at 37 degrees Celsius overnight in an incubator filled with 5%carbon dioxide atmosphere.Open the two three-way stopcocks and flush away bubbles in the channels by manually pumping the coating solution back and forth in the channel using the two syringes. Draw three milliliters of complete medium into a three milliliter syringe that connects to the three-way stopcock of the medium inlet and add it to replace the coating solution in the cell culture regions. Replace the white finger-tight plug with the Luer adapter and inject 3%hot agarose to fill the adapter.Connect the Luer lock syringe to the Luer adapter and inject 3%hot agarose through the black rubber bong to fill the Luer lock syringe. Allow 10 to 20 minutes for the agarose to cool down and solidify. Install the cell seeded MOE chip onto the transparent ITO heater that is fastened on a programmable XYZ motorized stage maintained at 37 degrees Celsius.Infuse the mNPCs by manually pumping into the MOE chip via the medium outlet, then incubate the cell seeded MOE chip on the ITO heater for four hours. Use electrical wires to connect an EF multiplexer to the MOE chip via the electrodes on the chip. Connect an EF multiplexer and a function generator to an amplifier to output square wave DC pulses.Remove all the flat bottom connector and adapters on the MOE chip and fill the adapters with PBS, then seal the adapter openings with parafilm. After immunostaining, observe the cells using a confocal fluorescence microscope. The DC pulse stimulation resulted in simultaneous mNPCs differentiating into neurons, astrocytes, and oligodendrocytes in stem cell maintenance medium.The percentages of neurons, astrocytes, and oligodendrocytes in the control group and in the stimulation group are shown here. After the DC pulse treatment, the mNPCs expressed significantly high numbers of neurons at DIV seven, astrocytes at DIV three, and oligodendrocytes at DIV seven and DIV 14 were present at relatively higher levels in the stimulation groups than in the control group. Neurospheres formed by 30 to 40 cells are preferred for initiating mNPC differentiation.Overgrowth of mNPCs will impair cell survival during the differentiation process.

electric-field-induced-neural-precursor-cell-differentiation

Research

JoVE Journal

Bioengineering

3.5K vistas.  Academia Sinica. Este estudio presenta un protocolo para la diferenciación de las células precursoras neuronales inducidas únicamente por la estimulación directa del pulso de corriente en un sistema microfluídico. Esta técnica proporciona un enfoque beneficioso para reducir el tiempo de configuración experimental, el volumen de la muestra y el volumen de reactivos. Además, el chip MOE es adecuado para observaciones de microscopía confocal.El tratamiento simple del pulso de corriente directa pu...