Name: an all-on-chip method for rapid neutrophil chemotaxis analysis directly from a drop of blood
Uploaded: 2017-06-23T13:00:00
Description: Watch this Scientific Journal Video about An All-on-chip Method for Rapid Neutrophil Chemotaxis Analysis Directly from a Drop of Blood at JoVE.com

This work is in part supported by grants from the Natural Sciences and Engineering Research Council of Canada (NSERC) and the Canadian Institutes of Health Research (CIHR). We thank the Clinical Institute of Applied Research and Education at the Victoria General Hospital in Winnipeg and Seven Oaks General Hospital in Winnipeg for managing clinical samples from human subjects. We thank Dr. Hagit Peretz-Soroka for helpful discussion about the assay operation strategies.
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We thank Professor Carolyn Ren and Dr. Xiaoming (Cody) Chen from the University of Waterloo for their generous support in the filming process.

All human sample collection protocols were approved by the Joint-Faculty Research Ethics Board at the University of Manitoba, Winnipeg.
1. Microfluidic Device Fabrication (Figure 1A)
<ol>
	<li>Design and print transparency mask.
	<ol>
		<li>Design the device as detailed previously25. See Figure 1A. 
		NOTE: The device includes two layers. The first layer (4 &#181;m high) defines the cell...

<ol>
	<li>Kolaczkowska, E., Kubes, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neutrophil+recruitment+and+function+in+health+and+inflammation.">Neutrophil recruitment and function in health and inflammation.</a> Nat Rev Immunol. 13 (13), 159-175 (2013).</li><li>Luster, A. D., Alon, R., von Andrian, U. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Immune+cell+migration+in+inflammation:+present+and+future+therapeutic+targets.">Immune cell migration in inflammation: present and future therapeutic targets.</a> Nat Immunol. 6 (12), 1182-1190 (2005).</li><li>Griffith, J. W., Luster, A. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Targeting+cells+in+motion:+migrating+toward+improved+therapies.">Targeting cells in motion: migrating toward improved therapies.</a> Eur. J. Immunol. 43 (6), 1430-1435 (2013).</li><li>Laird, D. J., von Andrian, U. H., Wagers, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stem+cell+trafficking+in+tissue+development,+growth,+and+disease.">Stem cell trafficking in tissue development, growth, and disease.</a> Cell. 132 (4), 612-630 (2008).</li><li>Condeelis, J., Segall, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intravital+imaging+of+cell+movement+in+tumours.">Intravital imaging of cell movement in tumours.</a> Nat Rev Cancer. 3 (12), 921-930 (2003).</li><li>Kruger, P., 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=Neutrophils:+between+host+defence,+immune+modulation,+and+tissue+injury.">Neutrophils: between host defence, immune modulation, and tissue injury.</a> PLoS Pathog. 11 (3), e1004651 (2015).</li><li>M&#243;csai, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diverse+novel+functions+of+neutrophils+in+immunity,+inflammation,+and+beyond.">Diverse novel functions of neutrophils in immunity, inflammation, and beyond.</a> J Exp Med. 210 (7), 1283-1299 (2013).</li><li>Foxman, E. F., Campbell, J. J., Butcher, E. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multistep+navigation+and+the+combinatorial+control+of+leukocyte+chemotaxis.">Multistep navigation and the combinatorial control of leukocyte chemotaxis.</a> J Cell Biol. 139 (7), 1349-1360 (1997).</li><li>Tazzyman, S., Niaz, H., Murdoch, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neutrophil-mediated+tumour+angiogenesis:+subversion+of+immune+responses+to+promote+tumour+growth.">Neutrophil-mediated tumour angiogenesis: subversion of immune responses to promote tumour growth.</a> Semin Cancer Biol. 23 (3), 149-158 (2013).</li><li>Boyden, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+chemotactic+effect+of+mixtures+of+antibody+and+antigen+on+polymorphonuclear+leucocytes.">The chemotactic effect of mixtures of antibody and antigen on polymorphonuclear leucocytes.</a> J Exp Med. 115 (3), 453-466 (1962).</li><li>Wu, J., Wu, X., Lin, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+developments+in+microfluidics-based+chemotaxis+studies.">Recent developments in microfluidics-based chemotaxis studies.</a> Lab Chip. 13 (13), 2484-2499 (2013).</li><li>Sackmann, E. K., Fulton, A. L., Beebe, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+present+and+future+role+of+microfluidics+in+biomedical+research.">The present and future role of microfluidics in biomedical research.</a> Nature. 507 (7491), 181-189 (2014).</li><li>Kim, S., Kim, H. J., Jeon, N. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biological+applications+of+microfluidic+gradient+devices.">Biological applications of microfluidic gradient devices.</a> Integr Biol. 2 (11-12), 584-603 (2010).</li><li>Irimia, D., 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=Microfluidic+system+for+measuring+neutrophil+migratory+responses+to+fast+switches+of+chemical+gradients.">Microfluidic system for measuring neutrophil migratory responses to fast switches of chemical gradients.</a> Lab Chip. 6 (2), 191-198 (2006).</li><li>Lin, F., 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=Neutrophil+migration+in+opposing+chemoattractant+gradients+using+microfluidic+chemotaxis+devices.">Neutrophil migration in opposing chemoattractant gradients using microfluidic chemotaxis devices.</a> Ann Biomed Eng. 33 (4), 475-482 (2005).</li><li>Ambravaneswaran, V., Wong, I. Y., Aranyosi, A. J., Toner, M., Irimia, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Directional+decisions+during+neutrophil+chemotaxis+inside+bifurcating+channels.">Directional decisions during neutrophil chemotaxis inside bifurcating channels.</a> Integr Biol. 2 (11-12), 639-647 (2010).</li><li>Jones, C. N., 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=Spontaneous+neutrophil+migration+patterns+during+sepsis+after+major+burns.">Spontaneous neutrophil migration patterns during sepsis after major burns.</a> PloS One. 9 (12), e114509 (2014).</li><li>Butler, K. 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=Burn+injury+reduces+neutrophil+directional+migration+speed+in+microfluidic+devices.">Burn injury reduces neutrophil directional migration speed in microfluidic devices.</a> PloS One. 5 (7), e11921 (2010).</li><li>Wu, 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=A+microfluidic+platform+for+evaluating+neutrophil+chemotaxis+induced+by+sputum+from+COPD+patients.">A microfluidic platform for evaluating neutrophil chemotaxis induced by sputum from COPD patients.</a> PloS One. 10 (5), e0126523 (2015).</li><li>Sackmann, E. K., 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=Microfluidic+kit-on-a-lid:+a+versatile+platform+for+neutrophil+chemotaxis+assays.">Microfluidic kit-on-a-lid: a versatile platform for neutrophil chemotaxis assays.</a> Blood. 120 (14), e45-e53 (2012).</li><li>Agrawal, N., Toner, M., Irimia, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neutrophil+migration+assay+from+a+drop+of+blood.">Neutrophil migration assay from a drop of blood.</a> Lab Chip. 8 (12), 2054-2061 (2008).</li><li>Jones, C. N., 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=Microfluidic+platform+for+measuring+neutrophil+chemotaxis+from+unprocessed+human+whole+blood.">Microfluidic platform for measuring neutrophil chemotaxis from unprocessed human whole blood.</a> J Vis Exp. (88), (2014).</li><li>Jones, C. N., 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=Microfluidic+assay+for+precise+measurements+of+mouse,+rat,+and+human+neutrophil+chemotaxis+in+whole-blood+droplets.">Microfluidic assay for precise measurements of mouse, rat, and human neutrophil chemotaxis in whole-blood droplets.</a> J Leukocyte Biol. 100 (1), 241-247 (2016).</li><li>Sackmann, E. K. -. 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=Characterizing+asthma+from+a+drop+of+blood+using+neutrophil+chemotaxis.">Characterizing asthma from a drop of blood using neutrophil chemotaxis.</a> P Natl Acad Sci. 111 (16), 5813-5818 (2014).</li><li>Wu, 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=An+all-on-chip+method+for+testing+neutrophil+chemotaxis+induced+by+fMLP+and+COPD+patient's+sputum.">An all-on-chip method for testing neutrophil chemotaxis induced by fMLP and COPD patient's sputum.</a> Technology. 04 (02), 104-109 (2016).</li></ol>

In this paper, a detailed protocol to directly isolate neutrophils from whole blood followed by the chemotaxis test, all on a single microfluidic chip, was described. This method offers useful features in its easy operation, negative selection of high purity neutrophils, rapid sample-to-result chemotaxis test, reduced reagents and sample consumption, and accurate cell migration data analysis. As a rough estimate, at least 25% of the neutrophils from the input whole blood sample effectively entered the docking structure i...

Chemotaxis, a process of directed cell migration to soluble chemical concentration gradient, is critically involved in many biological processes including immune response1,2,3, tissue development4 and cancer metastasis5. Neutrophils are the most abundant white blood cell subset and play crucial roles in enabling the body&#39;s innate host defense functions, as well as in mediating adaptive immune responses6,7. Neutrophils are equipped with highly-regulated chemotactic machinery allowing these motile immune cells to respond to both pathogen-derived chemoattractants (e.g. fMLP) and host-derived chemoattractants (e.g. interleukin-8) throughchemotaxis8. Neutrophil migration and chemotaxis mediate various physiological problems and diseases such as inflammation and cancers1,9. Thus, the accurate assessment of neutrophil chemotaxis provides an important functional readout for studying the neutrophil biology and the associated diseases.
Compared to the widely-used conventional chemotaxis assays (e.g. transwell assay10), the microfluidic devices show great promise for quantitative evaluation of cell migration and chemotaxis owing to the precisely controlled chemical gradient generation and miniaturization11,12,13. Over the last two decades or so, various microfluidic devices have been developed to study the chemotaxis of different biological cell types, especially neutrophils11. Significant effort was devoted to characterizing neutrophil migration in spatiotemporally complex chemical gradients that were configured in the microfluidic devices14,15. Interesting strategies were also developed to study directional decision making by neutrophils using the microfluidic devices16.Aside from biologically-oriented research, the applications of microfluidic devices have been extended to test clinical samples for disease evaluation17,18,19. However, the use of many microfluidic devices is limited to specialized research laboratories and requires lengthy neutrophil isolation from large volume of blood samples. Therefore, there has been a growing trend of developing integrated microfluidic devices for rapid neutrophil chemotaxis analysis directly from a drop of whole blood20,21,22,23,24.
Toward this direction, an all-on-chip method was developed that integrates the magnetic negative neutrophil purification and the subsequent chemotaxis assay on a single microfluidic device25. This all-on-chip method has the following novel features: 1) in contrast to previous on-chip strategies that isolate neutrophils from the blood by adhesion-based cell capture or cell size-based filtering20,22, this new method permits high purity, on-chip magnetic separation of the neutrophils from small volumes of whole blood, as well as chemotaxis measurement upon chemoattractant stimulation; 2) the cell docking structure helps align the initial positions of the neutrophils close to the chemical gradient channel and permits simple chemotaxis analysis without single cell tracking; 3) the integration of the neutrophil isolation and chemotaxis assay on a single microfluidic device permits rapid sample-to-result chemotaxis analysis in 25 min when there is no interruption between experimental steps.
This paper provides a detailed protocol for the construction, operation and data analysis method of this all-on-chip chemotaxis assay. The paper demonstrates the effective use of the developed method for performing neutrophil chemotaxis by testing a known recombinant chemoattractant and complex chemotactic samples from patients, followed by a discussion on troubleshooting strategies, limitations and future directions.

<table border="0" cellpadding="0" cellspacing="0" width="581">
	<tbody>
		<tr height="20">
			<td height="20" style="height:20px;width:581px;">Device fabrication</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Mask aligner</td>
			<td>ABM</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Spinner</td>
			<td>Solitec</td>
			<td>5000</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Hotplate</td>
			<td>VWR</td>
			<td>11301-022</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Plasma cleaner</td>
			<td>Harrick Plasma</td>
			<td>PDC-001</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Vacuum dessicator</td>
			<td>Fisher Scientific</td>
			<td>08-594-15A</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Digital scale</td>
			<td>Ohaus</td>
			<td>CS200</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">SU-8 2000 thinner</td>
			<td>Microchem</td>
			<td>SU-8 2000</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">SU-8 2025 photoresist</td>
			<td>Microchem</td>
			<td>SU-8 2025</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">SU-8 developer</td>
			<td>Microchem</td>
			<td>SU-8 developer</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Si wafer</td>
			<td>Silicon, Inc</td>
			<td>LG2065</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">isopropyl alcohol</td>
			<td>Fisher Scientific</td>
			<td>A416-4</td>
			<td></td>
		</tr>
		<tr height="52">
			<td height="52" style="height:52px;width:159px;">(tridecafluoro-1,1,2,2-tetrahydrooctyl) trichlorosilane</td>
			<td>Gelest</td>
			<td>78560-45-9</td>
			<td></td>
		</tr>
		<tr height="35">
			<td height="35" style="height:35px;width:159px;">Polydimethylsiloxane 
			(PDMS)</td>
			<td>Ellsworth Adhesives</td>
			<td>2065622</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Petri Dish</td>
			<td>Fisher Scientific</td>
			<td>FB0875714</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Glass slides</td>
			<td>Fisher Scientific</td>
			<td>12-544-4</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Cutting pad</td>
			<td>N/A</td>
			<td>N/A</td>
			<td>Custom-made</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Punchers</td>
			<td>N/A</td>
			<td>N/A</td>
			<td>Custom-made</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:159px;">Name </td>
			<td>Source</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">On-chip cell isolation and chemotaxis assay</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:159px;">RPMI 1640</td>
			<td>Fisher Scientific</td>
			<td>SH3025502</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">DPBS</td>
			<td>Fisher Scientific</td>
			<td>SH3002802</td>
			<td></td>
		</tr>
		<tr height="35">
			<td height="35" style="height:35px;width:159px;">Bovine serum albumin 
			(BSA)</td>
			<td>Sigma-Aldrich</td>
			<td>SH3057402</td>
			<td style="width:164px;"></td>
		</tr>
		<tr height="34">
			<td height="34" style="height:34px;">Fibronectin</td>
			<td>VWR</td>
			<td>CACB356008</td>
			<td style="width:164px;"></td>
		</tr>
		<tr height="34">
			<td height="34" style="height:34px;">fMLP</td>
			<td>Sigma-Aldrich</td>
			<td>F3506-10MG</td>
			<td style="width:164px;"></td>
		</tr>
		<tr height="35">
			<td height="35" style="height:35px;width:159px;">Magnetic disks</td>
			<td style="width:124px;">Indigo Instruments</td>
			<td>44202-1</td>
			<td style="width:164px;">5 mm in diameter, 
			1 mm thick</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:159px;">FITC-Dextran</td>
			<td>Sigma-Aldrich</td>
			<td>FD10S</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;"> Rhodamine</td>
			<td> 
			Sigma-Aldrich</td>
			<td>R4127-5G</td>
			<td style="width:164px;"></td>
		</tr>
		<tr height="35">
			<td height="35" style="height:35px;width:159px;">Giemsa stain solution</td>
			<td style="width:124px;">Rowley Biochemical Inc.</td>
			<td style="width:135px;">G-472-1-8OZ</td>
			<td style="width:164px;"></td>
		</tr>
		<tr height="52">
			<td height="52" style="height:52px;width:159px;">EasySep Direct Human 
			Neutrophil Isolation 
			Kit</td>
			<td style="width:124px;">STEMCELL 
			Technologies Inc</td>
			<td>19666</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:159px;">Dithiothreitol</td>
			<td style="width:124px;">Sigma-Aldrich</td>
			<td>D0632</td>
			<td></td>
		</tr>
		<tr height="34">
			<td height="34" style="height:34px;width:159px;"> Nikon Ti-U inverted fluorescent microscope </td>
			<td style="width:124px;">Nikon</td>
			<td>Ti-U</td>
			<td></td>
		</tr>
		<tr height="35">
			<td height="35" style="height:35px;width:159px;">Microscope environmental chamber.</td>
			<td style="width:124px;">InVivo Scientific</td>
			<td>N/A</td>
			<td style="width:164px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:159px;"> CCD camera</td>
			<td style="width:124px;">Nikon</td>
			<td>DS-Fi1</td>
			<td></td>
		</tr>
	</tbody>
</table>

an all-on-chip method for rapid neutrophil chemotaxis analysis directly from a drop of blood

Neutrophil migration and chemotaxis are critical for our body's immune system. Microfluidic devices are increasingly used for investigating neutrophil migration and chemotaxis owing to their advantages in real-time visualization, precise control of chemical concentration gradient generation, and reduced reagent and sample consumption. Recently, a growing effort has been made by the microfluidic researchers toward developing integrated and easily operated microfluidic chemotaxis analysis systems, directly from whole blood. In this direction, the first all-on-chip method was developed for integrating the magnetic negative purification of neutrophils and the chemotaxis assay from small blood volume samples. This new method permits a rapid sample-to-result neutrophil chemotaxis test in 25 min. In this paper, we provide detailed construction, operation and data analysis method for this all-on-chip chemotaxis assay with a discussion on troubleshooting strategies, limitations and future directions. Representative results of the neutrophil chemotaxis assay testing a defined chemoattractant, N-Formyl-Met-Leu-Phe (fMLP), and sputum from a chronic obstructive pulmonary disease (COPD) patient, using this all-on-chip method are shown. This method is applicable to many cell migration-related investigations and clinical applications.

Neutrophils are negatively selected from a drop of whole blood directly in the microfluidic device. The purity of the isolated neutrophils was verified by on-chip Giemsa staining and the results showed the typical ring-shaped and lobe-shaped nuclei of neutrophils (Figure 2A)25. This indicates an effective on-chip neutrophil isolation at high purity from a small volume of whole blood. Furthermore, the docking structure can effectively a...

Watch this Scientific Journal Video about An All-on-chip Method for Rapid Neutrophil Chemotaxis Analysis Directly from a Drop of Blood at JoVE.com

An All-on-chip Method for Rapid Neutrophil Chemotaxis Analysis Directly from a Drop of Blood

This article provides the detailed method of performing a rapid neutrophil chemotaxis assay by integrating the on-chip neutrophil isolation from whole blood and the chemotaxis test on a single microfluidic chip.

Neutrophil migration and chemotaxis are critical for our body's immune system. Microfluidic devices are increasingly used for investigating neutrophil ...

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Rapid Identification of Gram Negative Bacteria from Blood Culture Broth Using MALDI-TOF Mass Spectrometry

An important role of the clinical microbiology laboratory is to provide rapid identification of bacteria causing bloodstream infection. Traditional ...

Preparation of a Blood Culture Pellet for Rapid Bacterial Identification and Antibiotic Susceptibility Testing

Bloodstream infections and sepsis are a major cause of morbidity and mortality. The successful outcome of patients suffering from bacteremia depends on a ...

A RAPID Method for Blood Processing to Increase the Yield of Plasma Peptide Levels in Human Blood

Research in the field of food intake regulation is gaining importance. This often includes the measurement of peptides regulating food intake. For the ...

Establishment of a High-throughput Setup for Screening Small Molecules That Modulate c-di-GMP Signaling in Pseudomonas aeruginosa

Establishment of a High-throughput Setup for Screening Small Molecules That Modulate c-di-GMP Signaling in Pseudomonas aeruginosa

Bacterial resistance to traditional antibiotics has driven research attempts to identify new drug targets in recently discovered regulatory pathways. ...