We wish to thank members of the Ugarova laboratory and investigators in the Center for Metabolic and Vascular Biology for helpful discussion of this work. James Faust wishes to express his gratitude to the instructors at the European Molecular Biology Laboratory Super Resolution Microscopy course in 2015. We wish to thank Satya Khuon at Janelia for help with sample preparation for LLSM. During the review and filming portions of this work James Faust was supported by a T32 Fellowship (5T32DK007569-28). The Lattice Light Sheet component of this work was supported by HHMI and the Betty and Gordon Moore Foundation. T.U. is funded by NIH grant HL63199.

Procedures that utilize animals were approved by the Animal Care and Use Committees at Mayo Clinic, Janelia Research Campus, and Arizona State University.
1. Preparing Acid-cleaned Cover Glass
NOTE: Cover glass purchased from many manufacturers may not be as clean as expected. Consider routinely cleaning batches of cover glass before any procedure where microscopy is involved.
<ol>
	<li>Purchase high stringency cover glass. Take special care to choose the correct thickness (0.15 or 0.17 mm). 
	NOTE: The choice of cover glass thickness is dependent on the microscope objective and is listed directly on the objective barrel.</li>
	<li>Incubate the cover glass in 12 M hydrochloric acid in a well-ventilated chemical fume hood for 1 h with sonication (42 kHz, 70 W). Repeat this step for two additional times with fresh 12 M HCl.</li>
	<li>Fill a separate beaker with ultrapure water and add the cover glass. Sonicate the cover glass for 5 - 10 min in a well-ventilated chemical hood. Repeat this step ten times.</li>
	<li>Incubate the cover glass in pure acetone in a well-ventilated chemical hood for 30 min with sonication. Repeat this step for two additional times.</li>
	<li>Fill a separate beaker with sterile ultrapure water and add the cover glass. Sonicate the cover glass for 5 - 10 min in a well-ventilated chemical hood. Repeat this step ten times.</li>
	<li>Incubate the cover glass in 100% ethyl alcohol in a chemical hood for 30 min with sonication. Repeat this step two additional times. 
	NOTE: The purity of the ethyl alcohol is important. Contaminants in the form of dissolved solids will dry on the glass and can promote macrophage fusion.</li>
	<li>For long-term storage, place the acid-cleaned cover glass in a container filled with pure ethyl alcohol. Alternatively, dry the cover glass with nitrogen gas and store in a vacuum desiccator.</li>
</ol>
2. Preparation of Fusogenic Optical-quality Surfaces
<ol>
	<li>Dissolve DMSO-free high-melting point paraffin wax in ultrapure toluene. 
	NOTE: Stock concentrations are made at 10 mg/mL, and are diluted 1:9 in ultrapure toluene to make a 1 mg/mL working solution. 
	Caution: Toluene should be handled with care as a teratogen. Dispose of toluene according to the institutional chemical hygiene plan.</li>
	<li>Apply the paraffin working solution to a dry acid-cleaned cover glass at a volume that evenly covers the glass surface. Decant excess solution and dry the cover glass with nitrogen gas or air. For bulk preparation, use a Coplin jar designed to accommodate the cover glass.</li>
	<li>Polish the cover glass by 3 strokes in the x axis and next by 3 strokes in the y axis with a lint-free wipe (see Table of Materials).</li>
	<li>Immediately before the experiment is conducted, wash the cover glass with sterile ultrapure water, and subsequently sterilize for 15 - 30 min with ultraviolet light in a biological safety hood. Alternatively, sterilize the cover glass by ethylene oxide or gamma irradiation.</li>
</ol>
3. Micropatterning Hydrocarbon-containing Compounds to Confine Fusion to Predetermined Regions
<ol>
	<li>Dry the acid-cleaned cover glass and immobilize the glass on a flat surface.</li>
	<li>Using forceps, carefully immerse a gold transmission electron microscopy finder grid in a working solution of the hydrocarbon compound(s). Choose a hydrocarbon compound that meets the end goal of the experiment (see Table 1). Wick away excess solution by gently tapping the grid on filter paper, and immediately place the grid in the center of the cover glass. Allow the toluene to dry for 2 min before proceeding to the next step.</li>
	<li>Make sure the grid is bonded to the glass by gently inverting the glass. If the grid detaches repeat step 3.2 using a new cover glass. 
	NOTE: If a plasma cleaner is not available, omit step 3.4.</li>
	<li>Plasma clean the cover glass by treatment with vacuum gas plasma. 
	NOTE: The finder grid acts as a mask to protect the underlying surface adsorbed with long-chain hydrocarbons from the plasma. The regions that are unprotected by the grid are rendered non-fusogenic by exposure to plasma. The amount of time the cover glass is expose to plasma should be determined empirically.</li>
	<li>Using fine-tip forceps, carefully remove the grid from the glass surface to expose the micropattern.</li>
</ol>
4. Fabricating Glass Bottom Dishes
<ol>
	<li>Drill a 6 - 10 mm circular hole in the bottom of a 35-mm plastic Petri dish using a step drill bit. 
	NOTE: It is critical to use a step drill bit to create smooth edges. If edges are too rough, the cover glass will not bond flat to the bottom of the dish. Imperfectly flat surfaces make microscopy difficult.</li>
	<li>Carefully mix and degas silicone elastomer according to the manufacturer&#39;s instructions (i.e., polydimethylsiloxane; PDMS).</li>
	<li>Apply a thin coating of elastomer just proximate to the edge of (i.e., circumscribing) the hole. 
	NOTE: The elastomer should appear as a continuous albeit thin band surrounding the hole.</li>
	<li>Gently apply either the fusogenic cover glass (described in section 2), or the dry acid-cleaned cover glass (described in section 1) to the dish in order to cover the hole surrounded by elastomer. Ensure that the cover glass appears flush with the bottom of the dish and extends beyond the diameter of the hole so that a substantial portion of the glass is in contact with the plastic. Cure the elastomer by baking at 50 &#176;C for 2 - 3 h.</li>
	<li>If fusogenic glass is preferred, UV sterilize the dish and culture cells according to standard protocols. However, if a micropattern is preferred, proceed to step 3.2 for micropattern preparation (the gas plasma used during micropatterning sterilizes the dish and strongly couples PDMS to glass).</li>
</ol>
5. Collecting Thioglycollate-elicited Macrophages
<ol>
	<li>Inject 8-week-old C57BL/6 mice with 0.5 mL of a sterile solution of 4% Brewer&#39;s thioglycollate as previously described3,4,6.</li>
	<li>Seventy-two hours later, euthanize the animal according to approved animal care and use guidelines, and collect macrophages by peritoneal lavage with ice-cold phosphate-buffered saline supplemented with 5 mM ethylenediaminetetraacetate.</li>
	<li>Centrifuge the macrophages at 300 x g for 3 min and resuspend in 1 mL of DMEM:F12 supplemented with 15 mM HEPES, 10% FBS, and 1% antibiotics (culture medium). 
	NOTE: The cells are subsequently counted with a Neubauer hemocytometer. Macrophages are diluted to the appropriate concentration and applied to the surfaces. The number of cells to apply to a given surface should be carefully considered by the investigator for the purpose of the experimental question. Consult known standards in the primary literature.</li>
	<li>After 30 min wash the surfaces with HBSS supplemented with 0.1% BSA to remove non-adherent cells, and replace with fresh culture medium. Return the cultures to the incubator (5% CO2 in air at 37 &#176;C).</li>
	<li>2 h later, aspirate the medium and replace with culture medium supplemented with 10 ng/mL of IL-4. Image the cells as described elsewhere4.</li>
</ol>

<ol>
	<li>McNally, A. K., Anderson, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interleukin-4+induces+foreign+body+giant+cells+from+human+monocytes/macrophages.+Differential+lymphokine+regulation+of+macrophage+fusion+leads+to+morphological+variants+of+multinucleated+giant+cells.">Interleukin-4 induces foreign body giant cells from human monocytes/macrophages. Differential lymphokine regulation of macrophage fusion leads to morphological variants of multinucleated giant cells.</a> Am J Pathol. 147 (5), 1487 (1995).</li><li>Helming, L., Gordon, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+mediators+of+macrophage+fusion.">Molecular mediators of macrophage fusion.</a> Trends Cell Biol. 19 (10), 514-522 (2009).</li><li>Podolnikova, N. P., Kushchayeva, Y. S., Wu, Y., Faust, J., Ugarova, T. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Role+of+Integrins+&#945;+M+&#946;+2+(Mac-1,+CD11b/CD18)+and+&#945;+D+&#946;+2+(CD11d/CD18)+in+Macrophage+Fusion.">The Role of Integrins &#945; M &#946; 2 (Mac-1, CD11b/CD18) and &#945; D &#946; 2 (CD11d/CD18) in Macrophage Fusion.</a> Am J Pathol. 186 (8), 2105-2116 (2016).</li><li>Faust, J. J., Christenson, W., Doudrick, K., Ros, R., Ugarova, T. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+fusogenic+glass+surfaces+that+impart+spatiotemporal+control+over+macrophage+fusion:+Direct+visualization+of+multinucleated+giant+cell+formation.">Development of fusogenic glass surfaces that impart spatiotemporal control over macrophage fusion: Direct visualization of multinucleated giant cell formation.</a> Biomaterials. 128, 160-171 (2017).</li><li>Jenney, C. R., Anderson, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Alkylsilane-modified+surfaces:+Inhibition+of+human+macrophage+adhesion+and+foreign+body+giant+cell+formation.">Alkylsilane-modified surfaces: Inhibition of human macrophage adhesion and foreign body giant cell formation.</a> J Biomed Mater Res. 46 (1), 11-21 (1999).</li><li>Vignery, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Methods+to+fuse+macrophages+in+vitro.">Methods to fuse macrophages in vitro.</a> Cell Fusion: Overviews Methods. , 383-395 (2008).</li><li>Zhao, Q., 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=Foreign-body+giant+cells+and+polyurethane+biostability:+In+vivo+correlation+of+cell+adhesion+and+surface+cracking.">Foreign-body giant cells and polyurethane biostability: In vivo correlation of cell adhesion and surface cracking.</a> J Biomed Mater Res. 25 (2), 177-183 (1991).</li><li>Anderson, J. M., Rodriguez, A., Chang, D. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Foreign+body+reaction+to+biomaterials.">Foreign body reaction to biomaterials.</a> Semin Immunol. 20 (2), 86-100 (2008).</li><li>Jenney, C. R., Anderson, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+surface-coupled+polyethylene+oxide+on+human+macrophage+adhesion+and+foreign+body+giant+cell+formation+in+vitro.">Effects of surface-coupled polyethylene oxide on human macrophage adhesion and foreign body giant cell formation in vitro.</a> J Biomed Mater Res. 44 (2), 206-216 (1999).</li><li>DeFife, K. M., Colton, E., Nakayama, Y., Matsuda, T., Anderson, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spatial+regulation+and+surface+chemistry+control+of+monocyte/macrophage+adhesion+and+foreign+body+giant+cell+formation+by+photochemically+micropatterned+surfaces.">Spatial regulation and surface chemistry control of monocyte/macrophage adhesion and foreign body giant cell formation by photochemically micropatterned surfaces.</a> J Biomed Mater Res. 45 (2), 148-154 (1999).</li><li>Jenney, C. R., DeFife, K. M., Colton, E., Anderson, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+monocyte/macrophage+adhesion,+macrophage+motility,+and+IL-4-induced+foreign+body+giant+cell+formation+on+silane-modified+surfaces+in+vitro.">Human monocyte/macrophage adhesion, macrophage motility, and IL-4-induced foreign body giant cell formation on silane-modified surfaces in vitro.</a> J Biomed Mater Res. 41 (2), 171-184 (1998).</li><li>Hell, S. W., Wichmann, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Breaking+the+diffraction+resolution+limit+by+stimulated+emission:+stimulated-emission-depletion+fluorescence+microscopy.">Breaking the diffraction resolution limit by stimulated emission: stimulated-emission-depletion fluorescence microscopy.</a> Opt Lett. 19 (11), 780-782 (1994).</li><li>van de Linde, S., 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=Direct+stochastic+optical+reconstruction+microscopy+with+standard+fluorescent+probes.">Direct stochastic optical reconstruction microscopy with standard fluorescent probes.</a> Nat Protocols. 6 (7), 991-1009 (2011).</li><li>F&#246;lling, J., 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=Fluorescence+nanoscopy+by+ground-state+depletion+and+single-molecule+return.">Fluorescence nanoscopy by ground-state depletion and single-molecule return.</a> Nat Methods. 5 (11), 943-945 (2008).</li><li>Heilemann, 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=Subdiffraction-resolution+fluorescence+imaging+with+conventional+fluorescent+probes.">Subdiffraction-resolution fluorescence imaging with conventional fluorescent probes.</a> Ange Chem Int Edit. 47 (33), 6172-6176 (2008).</li><li>Betzig, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Proposed+method+for+molecular+optical+imaging.">Proposed method for molecular optical imaging.</a> Optics Letters. 20 (3), 237-239 (1995).</li><li>Betzig, E., 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=Imaging+intracellular+fluorescent+proteins+at+nanometer+resolution.">Imaging intracellular fluorescent proteins at nanometer resolution.</a> Science. 313 (5793), 1642-1645 (2006).</li><li>Shtengel, G., 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=Interferometric+fluorescent+super-resolution+microscopy+resolves+3D+cellular+ultrastructure.">Interferometric fluorescent super-resolution microscopy resolves 3D cellular ultrastructure.</a> P Natl Acad Sci U S A. 106 (9), 3125-3130 (2009).</li><li>Shtengel, G., 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=Imaging+cellular+ultrastructure+by+PALM,+iPALM,+and+correlative+iPALM-EM.">Imaging cellular ultrastructure by PALM, iPALM, and correlative iPALM-EM.</a> Method Cell Biol. 123, 273-294 (2013).</li><li>Chen, B. 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The authors declare that they have no competing financial interests.

The need to identify and subsequently develop optical-quality glass surfaces that promote macrophage fusion stemmed from the fact that until recently no published study directly visualized macrophage fusion in the context of living specimens3,4. This is due to the fact that fusogenic plastic surfaces that are commonly used require LWD objectives and are largely limited to phase contrast optics. These barriers were overcome by engineering an optical-quality glass ...

The formation of MGCs accompanies a number of pathological states in the human body distinguished by chronic inflammation1. Despite agreement that mononucleated macrophages fuse to form MGCs2, surprisingly few studies have shown fusion in context with living specimens3,4. This is because clean glass surfaces that are required for most imaging techniques do not promote macrophage fusion when induced by inflammatory cytokines5. Indeed, if clean glass is used as a substrate for macrophage fusion, then low to intermediate magnification objectives (i.e., 10 - 20X) and more than 15 h of continuous imaging are often required to observe a single fusion event.
On the other hand, fusogenic plastic surfaces (e.g., permanox) or bacteriological grade plastic promote fusion2. However, imaging through plastic is problematic because the substrate is thick and scatters light. This complicates imaging since long working distance (LWD) objectives are required. However, LWD objectives usually have low light gathering capacity compared to their coverslip-corrected counterpart. Further, techniques that exploit changes in the polarity of light passing through the specimen such as differential interference contrast are impossible since plastic is birefringent. The barriers associated with the use of plastic are further underscored by the fact that it is impossible to predict where macrophage fusion/MGC formation will occur on the surface. Together, these limitations restrict the visualization of macrophage fusion to phase contrast optics, extended total imaging durations (&#62;15 continuous hours), and low resolution.
We recently identified a highly fusogenic glass surface while conducting single-molecule super resolution microscopy with fixed macrophages/MGCs4. This observation was surprising because clean glass surfaces promote fusion at the very low rate of ~ 5% after 24 h in the presence of interleukin-4 (IL-4) as determined by the fusion index4. We found that the capacity to promote fusion was due to oleamide contamination. Adsorption of oleamide or other compounds that similarly contained long-chain hydrocarbons made the glass fusogenic. The most fusogenic compound (paraffin wax) was micropatterned, and it imparted a high degree of spatiotemporal control over macrophage fusion and a 2-fold increase in the number of fusion events observed within the same amount of time compared to permanox. These optical-quality surfaces provided the first glimpse into the morphological features and kinetics that govern the formation of MGCs in living specimens.
In this protocol we describe the fabrication of a variety of glass surfaces that can be used to monitor the formation of MGCs from living specimens. In addition, we show that these surfaces are amenable to far-field super-resolution techniques. Surface fabrication is dependent on the goal of the experiment, and each surface is described with related examples in the proceeding text.

<table border="0" cellpadding="0" cellspacing="0" width="1000">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:160px;">Plasma cleaner</td>
			<td style="width:240px;">Harrick Plasma</td>
			<td style="width:129px;">PCD-32G</td>
			<td style="width:471px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Finder grid</td>
			<td>Electron microscopy sciences</td>
			<td>G400F1-Au</td>
			<td>any gold TEM grid will work</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Cover glass (22x22 mm)</td>
			<td>Thor Labs</td>
			<td>CG15CH</td>
			<td>use only high stringency cover glass</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Paraffin wax</td>
			<td>Sigma Aldrich</td>
			<td>17310</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Petrolatum</td>
			<td>Sigma Aldrich</td>
			<td>16415</td>
			<td>must be &#945;-tocopherol-free if substituted</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Oleamide</td>
			<td>Sigma Aldrich</td>
			<td>O2136</td>
			<td>prepare fresh</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Isopropanol</td>
			<td>Sigma Aldrich</td>
			<td>278475</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Toluene</td>
			<td>Sigma Aldrich</td>
			<td>244511</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Acetone</td>
			<td>VWR International</td>
			<td>BDH1101</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Ethanol</td>
			<td>Electron microscopy sciences</td>
			<td>15050</td>
			<td>use low dissolved solids ethanol</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Hydrochloric acid</td>
			<td>Fischer Scientific</td>
			<td>A144C-212</td>
			<td>use to acid wash cover glass</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Slyguard 184</td>
			<td>VWR International</td>
			<td>102092-312</td>
			<td>mix in a 1:10 ratio and cure at 50 &#176;C for 4 h</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">35 mm petri dish</td>
			<td>Santa Cruz Biotech</td>
			<td>sc-351864</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Dumont no. 5 forceps</td>
			<td>Electron microscopy sciences</td>
			<td>72705</td>
			<td>ideal for removing TEM grid in section 3.5</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">FBS</td>
			<td>Atlanta Biological</td>
			<td>S11550</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">DMEM:F12</td>
			<td>Corning</td>
			<td>10-092</td>
			<td>contains 15 mM HEPES</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Pen/Strept</td>
			<td>Corning</td>
			<td>30-002-Cl</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">HBSS</td>
			<td>Corning</td>
			<td>21-023</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">BSA solution</td>
			<td>Sigma Aldrich</td>
			<td>A9576</td>
			<td>use at 0.1% in HBSS to wash non-adherent macrophages</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">IL-4</td>
			<td>Genscript</td>
			<td>Z02996</td>
			<td>aliquot at 10 &#956;g/mL and store at -20 &#176;C</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">C57BL/6J</td>
			<td>Jackson Laboratory</td>
			<td>000664</td>
			<td>use for fixed samples or techniques that do not require contrast agents</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">eGFP-LifeAct mice</td>
			<td>n/a</td>
			<td>n/a</td>
			<td>use for live fluorescence imaging</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Kimwipe</td>
			<td>Kimberly Clark&#160;</td>
			<td>34155</td>
			<td>use to polish hydrocarbon adsorbed surfaces</td>
		</tr>
	</tbody>
</table>

fabricating optical-quality glass surfaces to study macrophage fusion

Visualizing the formation of multinucleated giant cells (MGCs) from living specimens has been challenging due to the fact that most live imaging techniques require propagation of light through glass, but on glass macrophage fusion is a rare event. This protocol presents the fabrication of several optical-quality glass surfaces where adsorption of compounds containing long-chain hydrocarbons transforms glass into a fusogenic surface. First, preparation of clean glass surfaces as starting material for surface modification is described. Second, a method is provided for the adsorption of compounds containing long-chain hydrocarbons to convert non-fusogenic glass into a fusogenic substrate. Third, this protocol describes fabrication of surface micropatterns that promote a high degree of spatiotemporal control over MGC formation. Finally, fabricating glass bottom dishes is described. Examples of use of this in vitro cell system as a model to study macrophage fusion and MGC formation are shown.

Physicochemical parameters of materials have dramatic effects on the extent of macrophage fusion7,8,9,10. Moreover, surface contaminants are known to promote macrophage fusion11. Therefore, it is important to start with clean cover glass as a negative control for macrophage fusion. When cleaned as described in protocol 1, the cover glass ...

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Fabricating Optical-quality Glass Surfaces to Study Macrophage Fusion

This protocol describes the fabrication of optical-quality glass surfaces adsorbed with compounds containing long-chain hydrocarbons that can be used to monitor macrophage fusion of living specimens and enables super-resolution microscopy of fixed specimens.

Visualizing the formation of multinucleated giant cells (MGCs) from living specimens has been challenging due to the fact that most live imaging ...

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7.2K Views.  Mayo Clinic. This protocol describes the fabrication of optical-quality glass surfaces adsorbed with compounds containing long-chain hydrocarbons that can be used to monitor macrophage fusion of living specimens and enables super-resolution microscopy of fixed specimens.

Video: Fabricating Optical-quality Glass Surfaces to Study Macrophage Fusion

Glass Wool Filters for Concentrating Waterborne Viruses and Agricultural Zoonotic Pathogens

The key first step in evaluating pathogen levels in suspected contaminated water is concentration. Concentration methods tend to be specific for a particular pathogen group, for example US Environmental Protection Agency Method 1623 for Giardia and Cryptosporidium1, which means multiple methods are required if the sampling program is targeting more than one pathogen group. Another drawback of current methods is the equipment can be complicated and expensive, for example the VIRADEL method with the 1MDS cartridge filter for concentrating viruses2. In this article we describe how to construct glass wool filters for concentrating waterborne pathogens. After filter elution, the concentrate is amenable to a second concentration step, such as centrifugation, followed by pathogen detection and enumeration by cultural or molecular methods. The filters have several advantages. Construction is easy and the filters can be built to any size for meeting specific sampling requirements. The filter parts are inexpensive, making it possible to collect a large number of samples without severely impacting a project budget. Large sample volumes (100s to 1,000s L) can be concentrated depending on the rate of clogging from sample turbidity. The filters are highly portable and with minimal equipment, such as a pump and flow meter, they can be implemented in the field for sampling finished drinking water, surface water, groundwater, and agricultural runoff. Lastly, glass wool filtration is effective for concentrating a variety of pathogen types so only one method is necessary. Here we report on filter effectiveness in concentrating waterborne human enterovirus, Salmonella enterica, Cryptosporidium parvum, and avian influenza virus.

Glass wool filters have been used to concentrate waterborne viruses by a number of research groups around the world. Here we show a simple approach for constructing glass wool filters and demonstrate the filters are also effective in concentrating waterborne viral, bacterial and protozoan pathogens.

The key first step in evaluating pathogen levels in suspected contaminated water is concentration.  Concentration methods tend to be specific for a ...

Chemoselective Modification of Viral Surfaces via Bioorthogonal Click Chemistry

The modification of virus particles has received a significant amount of attention for its tremendous potential for impacting gene therapy, oncolytic applications and vaccine development.1,2,3 Current approaches to modifying viral surfaces, which are mostly genetics-based, often suffer from attenuation of virus production, infectivity and cellular transduction.4,5 Using chemoselective click chemistry, we have developed a straightforward alternative approach which sidesteps these issues while remaining both highly flexible and accessible.1,2
The goal of this protocol is to demonstrate the effectiveness of using bioorthogonal click chemistry to modify the surface of adenovirus type 5 particles. This two-step process can be used both therapeutically1 or analytically,2,6 as it allows for chemoselective ligation of targeting molecules, dyes or other molecules of interest onto proteins pre-labeled with azide tags. The three major advantages of this method are that (1) metabolic labeling demonstrates little to no impact on viral fitness,1,7 (2) a wide array of effector ligands can be utilized, and (3) it is remarkably fast, reliable and easy to access.1,2,7
In the first step of this procedure, adenovirus particles are produced bearing either azidohomoalanine (Aha, a methionine surrogate) or the unnatural sugar O-linked N-azidoacetylglucosamine (O-GlcNAz), both of which contain the azide (-N3) functional group. After purification of the azide-modified virus particles, an alkyne probe containing the fluorescent TAMRA moiety is ligated in a chemoselective manner to the pre-labeled proteins or glycoproteins. Finally, an SDS-PAGE analysis is performed to demonstrate the successful ligation of the probe onto the viral capsid proteins. Aha incorporation is shown to label all viral capsid proteins (Hexon, Penton and Fiber), while O-GlcNAz incorporation results in labeling of Fiber only.
In this evolving field, multiple methods for azide-alkyne ligation have been successfully developed; however only the two we have found to be most convenient are demonstrated herein &#x2013; strain-promoted azide-alkyne cycloaddition (SPAAC) and copper-catalyzed azide-alkyne cycloaddition (CuAAC) under deoxygenated atmosphere.

Adenovirus particles are engineered to contain either the unnatural amino acid analogue azidohomoalanine or the azido sugar O-GlcNAz. The azide group of each is chemoselectively ligated via "click" chemistry reactions as a means of viral surface modification.

The modification of virus particles has received a significant amount of attention for its tremendous potential for impacting gene therapy, oncolytic ...

Investigation of Macrophage Polarization Using Bone Marrow Derived Macrophages

The article describes a readily easy adaptive in vitro model to investigate macrophage polarization. In the presence of GM-CSF/M-CSF, hematopoietic stem/progenitor cells from the bone marrow are directed into monocytic differentiation, followed by M1 or M2 stimulation. The activation status can be tracked by changes in cell surface antigens, gene expression and cell signaling pathways.

The article describes a readily easy adaptive in vitro model to investigate macrophage polarization. In the presence of GM-CSF/M-CSF, hematopoietic stem/progenitor cells from the bone marrow are directed into monocytic differentiation, followed by M1 or M2 stimulation. The activation status can be tracked by changes in cell surface antigens, gene expression and cell signaling pathways.

The article describes a readily easy adaptive in vitro model to investigate macrophage polarization. In the presence of GM-CSF/M-CSF, hematopoietic ...

An In vitro Model to Study Heterogeneity of Human Macrophage Differentiation and Polarization

Monocyte-derived macrophages represent an important cell type of the innate immune system. Mouse models studying macrophage biology suffer from the phenotypic and functional differences between murine and human monocyte-derived macrophages. Therefore, we here describe an in vitro model to generate and study primary human macrophages. Briefly, after density gradient centrifugation of peripheral blood drawn from a forearm vein, monocytes are isolated from peripheral blood mononuclear cells using negative magnetic bead isolation. These monocytes are then cultured for six days under specific conditions to induce different types of macrophage differentiation or polarization. The model is easy to use and circumvents the problems caused by species-specific differences between mouse and man. Furthermore, it is closer to the in vivo conditions than the use of immortalized cell lines. In conclusion, the model described here is suitable to study macrophage biology, identify disease mechanisms and novel therapeutic targets. Even though not fully replacing experiments with animals or human tissues obtained post mortem, the model described here allows identification and validation of disease mechanisms and therapeutic targets that may be highly relevant to various human diseases.

An In vitro Model to Study Heterogeneity of Human Macrophage Differentiation and Polarization

Monocyte-derived macrophages are important cells of the innate immune system. Here, we describe an easy to use in vitro model to generate these cells. Using gradient centrifugation, negative bead isolation and specific cell culture conditions, monocyte-derived macrophages can be generated for phenotypic and functional studies.

Monocyte-derived macrophages represent an important cell type of the innate immune system. Mouse models studying macrophage biology suffer from the ...

Bone Marrow-derived Macrophage Production

Macrophages are critical components of the innate and adaptive immune responses, and they are the first line of defense against foreign invaders because of their powerful microbicidal activities. Macrophages are widely distributed throughout the body and are present in the lymphoid organs, liver, lungs, gastrointestinal tract, central nervous system, bone, and skin. Because of their repartition, they participate in a wide range of physiological and pathological processes. Macrophages are highly versatile cells that are able to recognize microenvironmental alterations and to maintain tissue homeostasis. Numerous pathogens have evolved mechanisms to use macrophages as Trojan horses to survive, replicate in, and infect both humans and animals and to propagate throughout the body. The recent explosion of interest in evolutionary, genetic, and biochemical aspects of host-pathogen interactions has renewed scientific attention regarding macrophages. Here, we describe a procedure to isolate and cultivate macrophages from murine bone marrow that will provide large numbers of macrophages for studying host-pathogen interactions as well as other processes.

Macrophages have long been recognized as a critical component of the innate and adaptive immune responses. The recent explosion of knowledge pertaining to evolutionary, genetic, and biochemical aspects of the interaction between macrophages and microbes has renewed scientific attention to macrophages. This article describes a method to differentiate macrophages from mouse bone marrow.

Macrophages are critical components of the innate and adaptive immune responses, and they are the first line of defense against foreign invaders because ...

RNA Purification from Intracellularly Grown Listeria monocytogenes in Macrophage Cells

Analysis of the transcriptome of bacterial pathogens during mammalian infection is a valuable tool for studying genes and factors that mediate infection. However, isolating bacterial RNA from infected cells or tissues is a challenging task, since mammalian RNA mostly dominates the lysates of infected cells. Here we describe an optimized method for RNA isolation of Listeria monocytogenes bacteria growing within bone marrow derived macrophage cells. Upon infection, cells are mildly lysed and rapidly filtered to discard most of the host proteins and RNA, while retaining intact bacteria. Next, bacterial RNA is isolated using hot phenol-SDS extraction followed by DNase treatment. The extracted RNA is suitable for gene transcription analysis by multiple techniques. This method is successfully employed in our studies of Listeria monocytogenes gene regulation during infection of macrophage cells 1-4. The protocol can be easily modified to study other bacterial pathogens and cell types.

RNA Purification from Intracellularly Grown Listeria monocytogenes in Macrophage Cells

Here we describe a method for bacterial RNA isolation from Listeria monocytogenes bacteria growing inside murine macrophages. This technique can be used with other intracellular pathogens and mammalian host cells.

Analysis of the transcriptome of bacterial pathogens during mammalian infection is a valuable tool for studying genes and factors that mediate infection. ...

Swab Sampling Method for the Detection of Human Norovirus on Surfaces

Human noroviruses are a leading cause of epidemic and sporadic gastroenteritis worldwide. Because most infections are either spread directly via the person-to-person route or indirectly through environmental surfaces or food, contaminated fomites and inanimate surfaces are important vehicles for the spread of the virus during norovirus outbreaks.
We developed and evaluated a protocol using macrofoam swabs for the detection and typing of human noroviruses from hard surfaces. Compared with fiber-tipped swabs or antistatic wipes, macrofoam swabs allow virus recovery (range 1.2-33.6%) from toilet seat surfaces of up to 700 cm2. The protocol includes steps for the extraction of the virus from the swabs and further concentration of the viral RNA using spin columns. In total, 127 (58.5%) of 217 swab samples that had been collected from surfaces in cruise ships and long-term care facilities where norovirus gastroenteritis had been reported tested positive for GII norovirus by RT-qPCR. Of these 29 (22.8%) could be successfully genotyped. In conclusion, detection of norovirus on environmental surfaces using the protocol we developed may assist in determining the level of environmental contamination during outbreaks as well as detection of virus when clinical samples are not available; it may also facilitate monitoring of effectiveness of remediation strategies.

A macrofoam based sampling methodology was developed and evaluated for the detection and quantification of norovirus on environmental hard surfaces.

Human noroviruses are a leading cause of epidemic and sporadic gastroenteritis worldwide. Because most infections are either spread directly via the ...

A High-throughput Compatible Assay to Evaluate Drug Efficacy against Macrophage Passaged Mycobacterium tuberculosis

The early drug development process for anti-tuberculosis drugs is hindered by the inefficient translation of compounds with in vitro activity to effectiveness in the clinical setting. This is likely due to a lack of consideration for the physiologically relevant cellular penetration barriers that exist in the infected host. We recently established an alternative infection model that generates large macrophage aggregate structures containing densely packed M. tuberculosis (Mtb) at its core, which was suitable for drug susceptibility testing. This infection model is inexpensive, rapid, and most importantly BSL-2 compatible. Here, we describe the experimental procedures to generate Mtb/macrophage aggregate structures that would produce macrophage-passaged Mtb for drug susceptibility testing. In particular, we demonstrate how this infection system could be directly adapted to the 96-well plate format showing throughput capability for the screening of compound libraries against Mtb. Overall, this assay is a valuable addition to the currently available Mtb drug discovery toolbox due to its simplicity, cost effectiveness, and scalability.

A High-throughput Compatible Assay to Evaluate Drug Efficacy against Macrophage Passaged Mycobacterium tuberculosis

New models and assays that would improve the early drug development process for next-generation anti-tuberculosis drugs are highly desirable. Here, we describe a quick, inexpensive, and BSL-2 compatible assay to evaluate drug efficacy against Mycobacterium tuberculosis that can be easily adapted for high-throughput screening.

The early drug development process for anti-tuberculosis drugs is hindered by the inefficient translation of compounds with in vitro activity to ...

Overexpression and Purification of Human Cis-prenyltransferase in Escherichia coli

Prenyltransferases (PT) are a group of enzymes that catalyze chain elongation of allylic diphosphate using isopentenyl diphosphate (IPP) via multiple condensation reactions. DHDDS (dehydrodolichyl diphosphate synthase) is a eukaryotic long-chain cis-PT (forming cis double bonds from the condensation reaction) that catalyzes chain elongation of farnesyl diphosphate (FPP, an allylic diphosphate) via multiple condensations with isopentenyl diphosphate (IPP). DHDDS is of biomedical importance, as a non-conservative mutation (K42E) in the enzyme results in retinitis pigmentosa, ultimately leading to blindness. Therefore, the present protocol was developed in order to acquire large quantities of purified DHDDS, suitable for mechanistic studies. Here, the usage of protein fusion, optimized culture conditions and codon-optimization were used to allow the overexpression and purification of functionally active human DHDDS in E. coli. The described protocol is simple, cost-effective and time sparing. The homology of cis-PT among different species suggests that this protocol may be applied for other eukaryotic cis-PT as well, such as those involved in natural rubber synthesis.

Overexpression and Purification of Human Cis-prenyltransferase in Escherichia coli

A simple protocol for overexpression and purification of codon-optimized, human cis-prenyltransferase, under non-denaturing conditions, from Escherichia coli, is described, along with an enzymatic activity assay. This protocol can be generalized for production of other cis- prenyltransferase proteins in quantity and quality suitable for mechanistic studies.

Prenyltransferases (PT) are a group of enzymes that catalyze chain elongation of allylic diphosphate using isopentenyl diphosphate (IPP) via multiple ...

Visualizing Macrophage Extracellular Traps Using Confocal Microscopy

A primary method used to define the presence of neutrophil extracellular traps (NETs) is confocal microscopy. We have modified established confocal microscopy methods to visualize macrophage extracellular traps (METs). These extracellular traps are defined by the presence of extracellular chromatin with co-expression of other components such as granule proteases, citrullinated histones, and peptidyl arginase deiminase (PAD). The expression of METs is generally measured after exposure to a stimulus and compared to un-stimulated samples. Samples are also included for background and isotype control. Cells are analyzed using well-defined image analysis software. Confocal microscopy may be used to define the presence of METs both in vitro and in vivo in lung tissue.

Macrophage extracellular traps are a newly described entity. This article will concentrate on confocal microscopy methods and how they are visualized in vitro and in vivo from lung samples.

A primary method used to define the presence of neutrophil extracellular traps (NETs) is confocal microscopy. We have modified established confocal ...