This work was supported by a start-up funding of Cincinnati Children&#8217;s Research Foundation and a University of Cincinnati Pilot Translational grant to M.N.&#160;We would like to thank the Cincinnati Children&#8217;s Hospital Research Flow Cytometry Core for their services.

Mouse blood collection should be conducted with appropriate institutional animal care and use committee approval.
NOTE: The platelet purification protocol is described in a flow diagram in Figure 1.
1. Collection of Blood
<ol>
	<li>Add 25 &#181;L of 3.2% sodium citrate (pH 7.2) as an anti-coagulant and 0.4 mM of Gly-Pro-Arg-Pro (GPRP) in a polypropylene tube.</li>
	<li>Collect approximately 200 &#181;L of bloo...

<ol>
	<li>de Witt, S. M., Verdoold, R., Cosemans, J. M., Heemskerk, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Insights+into+platelet-based+control+of+coagulation.">Insights into platelet-based control of coagulation.</a> Thrombosis Research. 133, S139-S148 (2014).</li><li>Machlus, K. R., Thon, J. N., Italiano, 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=Interpreting+the+developmental+dance+of+the+megakaryocyte:+a+review+of+the+cellular+and+molecular+processes+mediating+platelet+formation.">Interpreting the developmental dance of the megakaryocyte: a review of the cellular and molecular processes mediating platelet formation.</a> British Journal of Haematology. 165 (2), 227-236 (2014).</li><li>Weyrich, A. S., Zimmerman, G. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Platelets:+signaling+cells+in+the+immune+continuum.">Platelets: signaling cells in the immune continuum.</a> Trends in Immunology. 25 (9), 489-495 (2004).</li><li>Nami, 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=Crosstalk+between+platelets+and+PBMC:+New+evidence+in+wound+healing.">Crosstalk between platelets and PBMC: New evidence in wound healing.</a> Platelets. 27 (2), 143-148 (2016).</li><li>Mancuso, M. E., Santagostino, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Platelets:+much+more+than+bricks+in+a+breached+wall.">Platelets: much more than bricks in a breached wall.</a> British Journal of Haematology. 178 (2), 209-219 (2017).</li><li>Hampton, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Platelets'+Role+in+Adaptive+Immunity+May+Contribute+to+Sepsis+and+Shock.">Platelets' Role in Adaptive Immunity May Contribute to Sepsis and Shock.</a> Journals of the American Medical Association. 319 (13), 1311-1312 (2018).</li><li>Sabrkhany, S., Griffioen, A. W., Oude Egbrink, M. G. <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+blood+platelets+in+tumor+angiogenesis.">The role of blood platelets in tumor angiogenesis.</a> Biochimica et Biophysica Acta (BBA) - Reviews on Cancer. 1815 (2), 189-196 (2011).</li><li>Menter, D. 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=Platelet+&amp;#34;first+responders&amp;#34;+in+wound+response,+cancer,+and+metastasis.">Platelet &amp;#34;first responders&amp;#34; in wound response, cancer, and metastasis.</a> Cancer and Metastasis Reviews. 36 (2), 199-213 (2017).</li><li>Fink, 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=Characterization+of+platelet-specific+mRNA+by+real-time+PCR+after+laser-assisted+microdissection.">Characterization of platelet-specific mRNA by real-time PCR after laser-assisted microdissection.</a> Thrombosis and Haemostasis. 90 (4), 749-756 (2003).</li><li>Trichler, S. A., Bulla, S. C., Thomason, J., Lunsford, K. V., Bulla, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultra-pure+platelet+isolation+from+canine+whole+blood.">Ultra-pure platelet isolation from canine whole blood.</a> BioMed Central Veterinary Research. 9, 144 (2013).</li><li>Ford, T. C., Graham, J., Rickwood, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new,+rapid,+one-step+method+for+the+isolation+of+platelets+from+human+blood.">A new, rapid, one-step method for the isolation of platelets from human blood.</a> Clinica Chimica Acta. 192 (2), 115-119 (1990).</li><li>Noisakran, 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=Infection+of+bone+marrow+cells+by+dengue+virus+in+vivo.">Infection of bone marrow cells by dengue virus in vivo.</a> Experimental Hematolology. 40 (3), 250-259 (2012).</li><li>Rickwood, D., Ford, T., Graham, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nycodenz:+a+new+nonionic+iodinated+gradient+medium.">Nycodenz: a new nonionic iodinated gradient medium.</a> Analytical Biochemistry. 123 (1), 23-31 (1982).</li><li>Graham, J. M., Ford, T., Rickwood, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+of+the+major+subcellular+organelles+from+mouse+liver+using+Nycodenz+gradients+without+the+use+of+an+ultracentrifuge.">Isolation of the major subcellular organelles from mouse liver using Nycodenz gradients without the use of an ultracentrifuge.</a> Analytical Biochemistry. 187 (2), 318-323 (1990).</li><li>Milligan, G. 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=A+lethal+model+of+disseminated+dengue+virus+type+1+infection+in+AG129+mice.">A lethal model of disseminated dengue virus type 1 infection in AG129 mice.</a> Journal of General Virology. 98 (10), 2507-2519 (2017).</li><li>Strassel, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lentiviral+gene+rescue+of+a+Bernard-Soulier+mouse+model+to+study+platelet+glycoprotein+Ibbeta+function.">Lentiviral gene rescue of a Bernard-Soulier mouse model to study platelet glycoprotein Ibbeta function.</a> Journal of Thrombosis and Haemostasis. 14 (7), 1470-1479 (2016).</li><li>Bergmeier, W., Boulaftali, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adoptive+transfer+method+to+study+platelet+function+in+mouse+models+of+disease.">Adoptive transfer method to study platelet function in mouse models of disease.</a> Thrombosis Research. 133, S3-S5 (2014).</li><li>Bakchoul, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recommendations+for+the+use+of+the+non-obese+diabetic/severe+combined+immunodeficiency+mouse+model+in+autoimmune+and+drug-induced+thrombocytopenia:+communication+from+the+SSC+of+the+ISTH.">Recommendations for the use of the non-obese diabetic/severe combined immunodeficiency mouse model in autoimmune and drug-induced thrombocytopenia: communication from the SSC of the ISTH.</a> Journal of Thrombosis and Haemostasis. 13 (5), 872-875 (2015).</li><li>Aurbach, K., Spindler, M., Haining, E. J., Bender, M., Pleines, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Blood+collection,+platelet+isolation+and+measurement+of+platelet+count+and+size+in+mice-a+practical+guide.">Blood collection, platelet isolation and measurement of platelet count and size in mice-a practical guide.</a> Platelets. , 1-10 (2018).</li><li>Jirouskova, M., Shet, A. S., Johnson, G. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+guide+to+murine+platelet+structure,+function,+assays,+and+genetic+alterations.">A guide to murine platelet structure, function, assays, and genetic alterations.</a> Journal of Thrombosis and Haemostasis. 5 (4), 661-669 (2007).</li><li>Birschmann, I., 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=Use+of+functional+highly+purified+human+platelets+for+the+identification+of+new+proteins+of+the+IPP+signaling+pathway.">Use of functional highly purified human platelets for the identification of new proteins of the IPP signaling pathway.</a> Thrombosis Research. 122 (1), 59-68 (2008).</li></ol>

The authors declare no conflict of interest.

Commonly, platelets are isolated by low-speed centrifugation which yields platelet-rich plasma that contains a significant number of blood cells, cellular debris, and plasma proteins which can interfere with the biochemical and physiological assays and needs further purification21. Therefore, it is important to use a rapid and simple method which can yield pure platelets without major contaminants. The protocol presented here describes the purification of platelets from mouse blood using a gradien...

Platelets are a component of blood that functions as an initiator of blood clotting in response to damage in the blood vessel. They gather at the site of injury to plug the vessel wall1. Platelets are anucleate fragments of cytoplasm derived from the megakaryocytes of the bone marrow under the influence of thrombopoietin and enter the circulation2. They are considered as metabolically active and capable of sensing extracellular environment by activating intracellular signaling cascades that result in platelet spreading, aggregation, and hemostatic plug formation1,3. Besides hemostasis/thrombosis and wound healing4, platelets play an important role in host inflammatory responses, angiogenesis, and metastatis3,5,6,7,8.
Platelets are purified from blood to study their biochemical and physiological properties, which should be free from other blood components. Since red blood cells (RBC) and white blood cells (WBC) contain significantly more RNA and proteins than platelets9,10, the presence of even a small number of these cells can interfere with transcriptomic and proteomic analyses of RNA and proteins derived from platelets. We found that purified platelets activated with thrombin bind antibody such as anti-GPIIb/IIIa (JON/A) and anti-P-selectin more efficiently than whole blood platelets.
Since platelets are fragile, it is important to treat the samples as mildly as possible. If the platelets are activated, they release their granule contents and ultimately degrade. Therefore, to keep the platelets&#8217; functional properties intact, it is important to maintain platelet quiescence during isolation. Several protocols have described isolation of platelets from human, dog, rat, and non-human primate by various methods1,10,11,12. Some of the methods require multiple steps such as collection of platelet-rich plasma by centrifugation, filtration by separation column, negative selection of platelets with RBC- and WBC-specific antibody conjugated to magnetic beads, and so on, which are time-consuming and may degrade platelets and their contents.
Ford and his colleagues described platelet purification from human blood using iohexol medium11. This method uses a similar volume of blood sample and medium during purification. Since humans yield a higher volume of blood, it is relatively easy to purify the platelets.
Iohexol is a universal density gradient inert medium that is freely soluble in water and used in the fractionation of nucleic acids, proteins, polysaccharides, and nucleoproteins13,14. It has low osmolality and is non-toxic, thus making it an ideal medium for purification of intact living cells11. It is a non-particulate medium; therefore, the distribution of cells in a gradient can be determined using hemocytometer, flow cytometer, or spectrophotometer. It does not interfere with most of the enzymatic or chemical reaction of the cells or cellular fragments after dilution.
The mouse serves as an important animal model for many human diseases15,16,17,18. There are a few published articles that describe purification of mouse platelets19,20. However, the mouse yields a relatively smaller volume of blood, which makes it difficult to purify platelets. If the same small volume of gradient medium and blood samples is used, the platelet layer cannot be clearly separated from RBC-WBC layer after centrifugation. In this article, we have described a quick and simple method of mouse platelet purification with three-fold more iohexol gradient medium relative to the blood sample volume and low speed centrifugation. We have also activated the purified platelets with thrombin and investigated their quality with flow cytometry and microscopy.

<table>
	<tbody>
		<tr>
			<td>APC rat anti-mouse/human CD62P (P-selectin)</td>
			<td>Thermoscientific</td>
			<td>17-0626-82</td>
			<td>Platelets activation marker</td>
		</tr>
		<tr>
			<td>Eppendorf tube</td>
			<td>Fisher Scientific</td>
			<td>14-222-166</td>
			<td>Tube for centifuge</td>
		</tr>
		<tr>
			<td>FACS DIVA software</td>
			<td>BD Biosciences</td>
			<td>Non-catalog item</td>
			<td>Analysis of platelets and whole blood</td>
		</tr>
		<tr>
			<td>FACS tube</td>
			<td>Fisher Scientific</td>
			<td>352008</td>
			<td>Tubes for flow cytomtery</td>
		</tr>
		<tr>
			<td>Fetal bovine serum (FBS)</td>
			<td>Invitrogen</td>
			<td>26140079</td>
			<td>Ingredient for staining buffer</td>
		</tr>
		<tr>
			<td>FITC rat anti-mouse CD41</td>
			<td>BD Biosciences</td>
			<td>553848</td>
			<td>Platelets marker</td>
		</tr>
		<tr>
			<td>Flow cytometer</td>
			<td>BD Biosciences</td>
			<td>Non-catalog item</td>
			<td>Analysis of platelets and whole blood</td>
		</tr>
		<tr>
			<td>FlowJo software</td>
			<td>FlowJo, Inc.</td>
			<td>Non-catalog item</td>
			<td>Analysis of platelets and whole blood</td>
		</tr>
		<tr>
			<td>Gly-Pro-Arg-Pro (GPRP)</td>
			<td>EMD Millipore</td>
			<td>03-34-0001</td>
			<td>Prevent platelet clot formation</td>
		</tr>
		<tr>
			<td>Hematocrit Capillary tube</td>
			<td>Fisher Scientific</td>
			<td>22-362566</td>
			<td>Blood collection capillary tube</td>
		</tr>
		<tr>
			<td>Hemavet</td>
			<td>Drew Scientific</td>
			<td>Non-catalog item</td>
			<td>Blood cell analyzer</td>
		</tr>
		<tr>
			<td>Hemocytometer</td>
			<td>Hausser Scientific</td>
			<td>3100</td>
			<td>Cell counting chamber</td>
		</tr>
		<tr>
			<td>Isoflurane</td>
			<td>Baxter</td>
			<td>1001936040</td>
			<td>Use to Anesthetize mouse</td>
		</tr>
		<tr>
			<td>Microscope (Olympus CKX41)</td>
			<td>Olympus</td>
			<td>Non-catalog item</td>
			<td>Cell monitoring and counting</td>
		</tr>
		<tr>
			<td>Nycodenz (Histodenz)</td>
			<td>Sigma-Aldrich</td>
			<td>D2158</td>
			<td>Gradient medium</td>
		</tr>
		<tr>
			<td>PE rat anti-mouse CD45</td>
			<td>BD Biosciences</td>
			<td>561087</td>
			<td>WBC marker</td>
		</tr>
		<tr>
			<td>PE-Cy7 rat anti-mouse TER 119</td>
			<td>BD Biosciences</td>
			<td>557853</td>
			<td>RBC marker</td>
		</tr>
		<tr>
			<td>Pipet tips 200 &#181;L, wide-bore</td>
			<td>ThermoFisher Scientific</td>
			<td>21-236-1A</td>
			<td>Transferring blood and platelet samples</td>
		</tr>
		<tr>
			<td>Pipet tips 1000 &#181;L, wide-bore</td>
			<td>ThermoFisher Scientific</td>
			<td>21-236-2C</td>
			<td>Transferring blood and platelet samples</td>
		</tr>
		<tr>
			<td>Phosphate buffured saline (PBS)</td>
			<td>ThermoFisher Scientific</td>
			<td>14040-117</td>
			<td>Buffer for washing and dilution</td>
		</tr>
		<tr>
			<td>Sodium chloride</td>
			<td>Sigma-Aldrich</td>
			<td>S7653</td>
			<td>Physiological saline</td>
		</tr>
		<tr>
			<td>Sodium citrate</td>
			<td>Fisher Scientific</td>
			<td>02-688-26</td>
			<td>Anti-coagulant</td>
		</tr>
		<tr>
			<td>Staining buffer</td>
			<td>In-house</td>
			<td>Non-catalog item</td>
			<td>Wash and dilution buffer</td>
		</tr>
		<tr>
			<td>Steile water</td>
			<td>In-house</td>
			<td>Non-catalog item</td>
			<td>Solvent</td>
		</tr>
		<tr>
			<td>Table top centrifuge</td>
			<td>ThermoFisher Scientific</td>
			<td>75253839/433607</td>
			<td>Swinging bucket rotor centrifuge</td>
		</tr>
		<tr>
			<td>Thrombin</td>
			<td>Enzyme Research Laboratoty</td>
			<td>HT 1002a</td>
			<td>Platelet activation agonist</td>
		</tr>
		<tr>
			<td>Tricine</td>
			<td>Sigma-Aldrich</td>
			<td>T0377</td>
			<td>Buffer for Nycodenz medium</td>
		</tr>
	</tbody>
</table>

purification of platelets from mouse blood

Platelets are purified from whole blood to study their functional properties, which should be free from red blood cells (RBC), white blood cells (WBC), and plasma proteins. We describe here purification of platelets from mouse blood using three-fold more iohexol gradient medium relative to blood sample volume and centrifugation in a swinging bucket rotor at 400 x g for 20 min at 20 &#176;C. The recovery/yield of the purified platelets were 18.2-38.5%, and the purified platelets were in a resting state, which did not contain any significant number of RBC and WBC. The purified platelets treated with thrombin showed up to 93% activation, indicating their viability. We confirmed that the purified platelets are sufficiently pure using flow cytometric and microscopic evaluation. These platelets can be used for gene expression, activation, granule release, aggregation, and adhesion assays. This method can be used for purification of platelets from the blood of other species as well.

The summary of platelet purification is described in a flow diagram (Figure 1). Steps include collection of blood from mouse using retro-orbital bleeding in the presence of an anticoagulant, addition of blood sample onto the iohexol gradient medium, centrifugation in a swinging bucket rotor at 400 x g for 20 min at 20 &#176;C. The quality of the purified platelets was evaluated with microscopy and flow cytometry after staining with antibody to detect any contaminating cells and acti...

Watch this Scientific Journal Video about Purification of Platelets from Mouse Blood at JoVE.com

Purification of Platelets from Mouse Blood

Here, mouse blood was collected in the presence of an anti-coagulant. The platelets were purified by iohexol gradient medium using low speed centrifugation. The platelets were activated with thrombin to investigate if they were viable. The quality of the purified platelets was analyzed by flow cytometry and microscopy.

Platelets are purified from whole blood to study their functional properties, which should be free from red blood cells (RBC), white blood cells (WBC), ...

Platelets should be free from blood cells and proteins when studying their biochemical and physiological properties. Therefore, we have developed a protocol to purify platelets from mouse blood. This technique can purify platelets using iohexol gradient medium and low-speed centrifugation, resulting in a clear separation of platelets from other blood components.To purify the platelets, use a wide-bore pipette tip to layer 200 microliters of freshly harvested whole blood slowly down the side of a 1.5-milliliter tube onto 600 microliters of iohexol gradient medium without mixing. After centrifugation in a swinging-bucket rotor to isolate the platelets, use a new wide-bore pipette tip to collect most of the platelet-rich layer and a small fraction of the platelet-poor layer without aspirating the white blood cell or red blood cell layer. Add the platelet sample to a new tube, and add one milliliter of PBS to the platelets.Mix the platelets by inversion before performing another centrifugation. Then resuspend the pellet in 200 microliters of PBS with mild pipetting. For platelet activation, transfer one to two times 10 to the six platelets to a new tube containing 100 microliters of staining buffer.Add one to two times 10 to the six platelets to a different tube containing 100 microliters of staining buffer supplemented with 0.4-millimolar GPRP peptide. Add thrombin to the tube with the GPRP peptide to activate the platelets, and add the antibody cocktail of interest to both tubes. As a positive control, add one microliter of whole blood in up to 100 microliters of staining buffer in a tube containing 0.4-millimolar GPRP peptide, and add thrombin to activate these platelets.As a negative control, add one microliter of whole blood in up to 100 microliters of staining buffer. Then stain both control tubes with the antibody cocktail. After 30 minutes at room temperature in the dark, wash the samples with one milliliter of fresh staining buffer per tube.Resuspend the pellets in 300 microliters of fresh staining buffer. Then transfer the cell samples into individual flow cytometry analysis tubes protected from light. To analyze the platelets by flow cytometry, create a new experiment, and generate logarithmic forward scatter versus logarithmic side scatter dot plots.After adjusting the voltages as necessary, record the single-color-stained cells for the compensation controls. Now run the positive control sample to acquire enough cells to adjust the compensation and the gates. Then acquire and record 100, 000 events for each whole blood sample, and analyze the flow cytometry data using the appropriate plots and gates.If the blood is added onto the medium slowly, the iohexol gradient medium and the blood sample will form two separate layers in the tube. After centrifugation, the top, straw-colored layer contains the plasma but no intact blood cells. The second, whitish, platelet-rich layer contains the majority of the platelets.The third, transparent layer is the platelet-poor layer and is directly above the red blood cell and white blood cell pellet. Whole blood exhibits distinct populations of red blood cells, white blood cells, and platelets on a logarithmic forward scatter versus side scatter dot plot. Purified platelets, however, demonstrate a distinct population with negligible numbers of red or white blood cells.Whole blood samples contain Ter119-positive red blood cell and CD45-positive white blood cell populations that are nearly absent in purified platelet samples. Untreated purified platelets express almost no activation markers confirming their resting state, whereas purified thrombin-treated platelets typically demonstrate a 71%P-selectin expression. Microscopic evaluation of untreated purified platelet samples reveals no platelet aggregation.After activation with thrombin, however, the platelets demonstrate a robust aggregation, further confirming their viability after purification as demonstrated. Layer the blood sample carefully onto the iohexol medium, and when collecting the platelets, be sure to aspirate carefully as to not collect the red blood cell and white blood cell layers for successful platelet purification. This method can be used for platelet purification from other species as well.The purified platelets can be used for gene expression, activation, aggregation, granule release, and adhesion studies.

purification-of-platelets-from-mouse-blood

Research

JoVE Journal

Biology

21.2K Views.  Cincinnati Children's Hospital Medical Center. Platelets should be free from blood cells and proteins when studying their biochemical and physiological properties. Therefore, we have developed a protocol to purify platelets from mouse blood. This technique can purify platelets using iohexol gradient medium and low-speed centrifugation, resulting in a clear separation of platelets from other blood components.To purify the platelets, use a wide-bore pipette tip to layer 200 microliters of freshly harvested whole blood slowly down the...