Name: protein digestion, ultrafiltration, and size exclusion chromatography to optimize the isolation of exosomes from human blood plasma and serum
Uploaded: 2018-04-13T15:00:00
Description: Watch this Scientific Journal Video about Protein Digestion, Ultrafiltration, and Size Exclusion Chromatography to Optimize the Isolation of Exosomes from Human Blood Plasma and Serum at JoVE.com

This research was supported by internal funds from CSU (to KMD), ATCC contract #2016-0550-0002 (a subcontract of NIAID HHSN272201600013C), and The Bill and Melinda Gates Foundation (OPP1039688) (to KMD/NKG). We thank the NSF Research Experience for Undergraduates (REU) summer program at Colorado State University for additional support.

This work was determined not to be human subject research upon initial review from Colorado State University&#39;s Institutional Review Board (IRB), as all human samples were obtained as de-identified samples from the Bioreclamation IVT biorepository and were collected under IRB approved protocols.
1. Preparation of Crude Sample (either Plasma or Serum) by Pelleting Larger Vesicles and Cellular Debris
Note: Safety consideration: plasma, serum, and oth...

<ol>
	<li>Stoorvogel, W., Kleijmeer, M. J., Geuze, H. J., Raposo, 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+biogenesis+and+functions+of+exosomes.">The biogenesis and functions of exosomes.</a> Traffic. 3 (5), 321-330 (2002).</li><li>Raposo, G., Stoorvogel, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extracellular+vesicles:+exosomes,+microvesicles,+and+friends.">Extracellular vesicles: exosomes, microvesicles, and friends.</a> J Cell Biol. 200 (4), 373-383 (2013).</li><li>Schorey, J. S., Harding, C. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extracellular+vesicles+and+infectious+diseases:+new+complexity+to+an+old+story.">Extracellular vesicles and infectious diseases: new complexity to an old story.</a> J Clin Invest. 126 (4), 1181-1189 (2016).</li><li>Taylor, D. D., Gercel-Taylor, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Exosome+platform+for+diagnosis+and+monitoring+of+traumatic+brain+injury.">Exosome platform for diagnosis and monitoring of traumatic brain injury.</a> Philos Trans R Soc Lond B Biol Sci. 369 (1652), (2014).</li><li>Nilsson, 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=Prostate+cancer-derived+urine+exosomes:+a+novel+approach+to+biomarkers+for+prostate+cancer.">Prostate cancer-derived urine exosomes: a novel approach to biomarkers for prostate cancer.</a> Br J Cancer. 100 (10), 1603-1607 (2009).</li><li>Linares, R., Tan, S., Gounou, C., Arraud, N., Brisson, A. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-speed+centrifugation+induces+aggregation+of+extracellular+vesicles.">High-speed centrifugation induces aggregation of extracellular vesicles.</a> J Extracell Vesicles. 4, 29509 (2015).</li><li>Lobb, R. 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=Optimized+exosome+isolation+protocol+for+cell+culture+supernatant+and+human+plasma.">Optimized exosome isolation protocol for cell culture supernatant and human plasma.</a> J Extracell Vesicles. 4, 27031 (2015).</li><li>Vergauwen, 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=Confounding+factors+of+ultrafiltration+and+protein+analysis+in+extracellular+vesicle+research.">Confounding factors of ultrafiltration and protein analysis in extracellular vesicle research.</a> Scientific Reports. 7 (1), 2704 (2017).</li><li>Welton, J. L., Webber, J. P., Botos, L. A., Jones, M., Clayton, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ready-made+chromatography+columns+for+extracellular+vesicle+isolation+from+plasma.">Ready-made chromatography columns for extracellular vesicle isolation from plasma.</a> J Extracell Vesicles. 4, 27269 (2015).</li><li>S&#243;dar, B. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Low-density+lipoprotein+mimics+blood+plasma-derived+exosomes+and+microvesicles+during+isolation+and+detection.">Low-density lipoprotein mimics blood plasma-derived exosomes and microvesicles during isolation and detection.</a> Sci Rep. 6, 24316 (2016).</li><li>de Menezes-Neto, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Size-exclusion+chromatography+as+a+stand-alone+methodology+identifies+novel+markers+in+mass+spectrometry+analyses+of+plasma-derived+vesicles+from+healthy+individuals.">Size-exclusion chromatography as a stand-alone methodology identifies novel markers in mass spectrometry analyses of plasma-derived vesicles from healthy individuals.</a> J Extracell Vesicles. 4, 27378 (2015).</li><li>Corso, 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=Reproducible+and+scalable+purification+of+extracellular+vesicles+using+combined+bind-elute+and+size+exclusion+chromatography.">Reproducible and scalable purification of extracellular vesicles using combined bind-elute and size exclusion chromatography.</a> Scientific Reports. 7 (1), 11561 (2017).</li><li>Diaz, G., Wolfe, L. M., Kruh-Garcia, N. A., Dobos, K. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Changes+in+the+Membrane-Associated+Proteins+of+Exosomes+Released+from+Human+Macrophages+after+Mycobacterium+tuberculosis+Infection.">Changes in the Membrane-Associated Proteins of Exosomes Released from Human Macrophages after Mycobacterium tuberculosis Infection.</a> Sci Rep. 6, 37975 (2016).</li><li>Yuana, Y., Levels, J., Grootemaat, A., Sturk, A., Nieuwland, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Co-isolation+of+extracellular+vesicles+and+high-density+lipoproteins+using+density+gradient+ultracentrifugation.">Co-isolation of extracellular vesicles and high-density lipoproteins using density gradient ultracentrifugation.</a> J Extracell Vesicles. 3, (2014).</li><li>Th&#233;ry, C., Amigorena, S., Raposo, G., Clayton, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+and+characterization+of+exosomes+from+cell+culture+supernatants+and+biological+fluids.">Isolation and characterization of exosomes from cell culture supernatants and biological fluids.</a> Curr Protoc Cell Biol. , (2006).</li><li>Muller, L., Hong, C. S., Stolz, D. B., Watkins, S. C., Whiteside, T. L. <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+biologically-active+exosomes+from+human+plasma.">Isolation of biologically-active exosomes from human plasma.</a> J Immunol Methods. 411, 55-65 (2014).</li><li>B&#246;ing, A. 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=Single-step+isolation+of+extracellular+vesicles+by+size-exclusion+chromatography.">Single-step isolation of extracellular vesicles by size-exclusion chromatography.</a> J Extracell Vesicles. 3, (2014).</li><li>Sweeney, P. J., Walker, 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=Proteinase+K+(EC+3.4.21.14).">Proteinase K (EC 3.4.21.14).</a> Methods Mol Biol. 16, 305-311 (1993).</li><li>Baranyai, 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=Isolation+of+Exosomes+from+Blood+Plasma:+Qualitative+and+Quantitative+Comparison+of+Ultracentrifugation+and+Size+Exclusion+Chromatography+Methods.">Isolation of Exosomes from Blood Plasma: Qualitative and Quantitative Comparison of Ultracentrifugation and Size Exclusion Chromatography Methods.</a> PLoS One. 10 (12), e0145686 (2015).</li></ol>

An optimized method to increase the purity and yield of exosomes from blood will increase the ability to accurately mine extracellular vesicles as a source of biomarkers for several diseases. The standard methods currently used to isolate exosomes, specifically, ultracentrifugation and precipitation methods, have several disadvantages including exosome aggregation and pelleting of soluble proteins7,17,18. Alternatively, the use ...

Exosomes are nanovesicles (ranging in size from 30 nm to 150 nm) released by almost all the cells in the human body to facilitate cell-to-cell communication processes1,2. Interestingly, the composition of exosomes changes depending on the cells of origin as well as the health status of the individual3,4,5. Additionally, exosomes can be retrieved from several biological fluids such as: saliva, urine, and blood2. Because of these features, exosomes are considered to be a good source of disease biomarkers. Unfortunately, there is no standard method for the isolation of exosomes. Some laboratories consider multistep centrifugation, with a final high-speed step at 100,000 x g using density gradients as the gold standard method for exosome isolation. However, recent studies have shown that ultracentrifugation induces aggregation of exosomes with soluble proteins and other exosomes, in addition to affecting exosome integrity, both of which may hamper downstream applications6,7. Other common methods of exosome isolation include, but are not limited to: precipitation by commercial polyethylene glycol (PEG) based reagents, centrifugal ultrafiltration, and size-exclusion chromatography (SEC). The commercial reagents using polyethylene glycol (PEG) polymers enrich exosomes by causing them to precipitate and form a pellet. Limitations using this polymer are contamination with residual PEG polymer and an abundance of soluble non-exosomal proteins in the final product. Ultrafiltration utilizes centrifugation to purify and concentrate vesicles using a cellulose membrane; exosomes are retained above the filter, while smaller impurities and other proteins pass through the membrane7,8. Just like other methods, centrifugal ultrafiltration has a limited capacity to purify exosomes due to the retention of high levels of non-exosomal proteins, including protein complexes and aggregates. Finally, SEC purification uses porous resin to separate molecules by size. SEC has shown promising results, overcoming most of the problems experienced with other methods by capturing the majority of contaminant proteins and preserving exosomal integrity, since isolation is based on gravity or low-pressure systems7,9. However, the co-isolation of larger protein aggregates and lipoproteins10 during SEC affects the purity of the final exosome preparation. While some methods have been tested for exosome purification from cell culture supernatants and plasma7, or only plasma9,11, there is no information about the performance of methods directly comparing blood plasma and serum from the same individual.
Here, we focus on the purification of blood exosomes by comparing a variety of workflows to determine if vesicle enrichment techniques are translatable between plasma and serum. Nanoparticle tracking analysis and western blot were used to quantify the differences in exosome concentration, purity, and protein composition in the end products. The final method, detailed in this protocol, increases vesicle numbers and reduces non-exosomal protein levels. Importantly, a drastic reduction of common co-precipitating proteins including albumin and apolipoproteins is demonstrated. The high abundance of these two proteins in blood and the frequency at which they co-purify with exosomes causes inconsistencies between &#34;purified&#34; samples, skewing the downstream analyses. This protocol includes the use of a commercially available SEC resin; the resin is composed of porous beads in which proteins smaller than 700 kDa can enter the beads. Once inside, the proteins are retained by an octylamine ligand. The eluate is composed of exosomes and molecules larger than 700 kDa12. Additionally, in order to reduce the protein aggregates and apolipoproteins which evade bead trapping, we include a protease digestion step in the workflow. Currently, there is no single technique capable of maximizing exosome yield while reducing co-purifying non-exosomal proteins. This study shows that a purification protocol that combines a protease digestion pretreatment with multiple recovery and purification methods can be used to increase exosome yield and purity from blood serum and plasma.

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			<td height="21" style="height:21px;width:281px;">Nanosight</td>
			<td style="width:149px;">Malvern</td>
			<td style="width:123px;">NS300</td>
			<td style="width:124px;"></td>
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			<td height="21" style="height:21px;width:281px;">Benchtop microcentrifuge&#160;</td>
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			<td style="width:123px;">Legend Mico21</td>
			<td style="width:124px;"></td>
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			<td height="21" style="height:21px;width:281px;">Benchtop centrifuge&#160;</td>
			<td style="width:149px;">Beckman Coulter</td>
			<td style="width:123px;">Allegra 6R</td>
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			<td height="21" style="height:21px;width:281px;">Waterbath&#160;</td>
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			<td height="21" style="height:21px;width:281px;">Microplate reader</td>
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			<td height="21" style="height:21px;width:281px;">Pierce BCA Protein Assay Kit</td>
			<td style="width:149px;">THERMO</td>
			<td style="width:123px;">23227</td>
			<td style="width:124px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:281px;">Micro BCA Protein Assay Kit</td>
			<td style="width:149px;">THERMO</td>
			<td style="width:123px;">23235</td>
			<td style="width:124px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:281px;">Phosphate buffered saline</td>
			<td style="width:149px;">Corning</td>
			<td style="width:123px;">21-040-CV</td>
			<td style="width:124px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:281px;">96 well plate</td>
			<td style="width:149px;">Corning</td>
			<td style="width:123px;">15705-066</td>
			<td style="width:124px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:281px;">Amicon Ultra-0.5 Centrifugal Filter Unit with Ultracel-100 membrane</td>
			<td style="width:149px;">EMD-Millipore</td>
			<td style="width:123px;">UFC510096</td>
			<td style="width:124px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:281px;">Amicon Ultra-4 Centrifugal Filter Units</td>
			<td style="width:149px;">EMD-Millipore</td>
			<td style="width:123px;">UFC800324</td>
			<td style="width:124px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:281px;">Capto Core 700</td>
			<td style="width:149px;">GE Healthcare</td>
			<td style="width:123px;">17548103</td>
			<td style="width:124px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:281px;">Poly-Prep&#160;Chromatography Columns</td>
			<td style="width:149px;">BIORAD</td>
			<td style="width:123px;">7311550</td>
			<td style="width:124px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:281px;">NuPAGE 4-12% Bis-Tris Protein Gels</td>
			<td style="width:149px;">THERMO</td>
			<td style="width:123px;">NP0323BOX</td>
			<td style="width:124px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:281px;">Nitrocellulose Membrane, Roll, 0.2 &#181;m</td>
			<td style="width:149px;">BIORAD</td>
			<td style="width:123px;">1620112</td>
			<td style="width:124px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:281px;">Proteinase K,&#160;Tritirachium album</td>
			<td style="width:149px;">EMD-Millipore</td>
			<td style="width:123px;">539480</td>
			<td style="width:124px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:281px;">SimplyBlue SafeStain</td>
			<td style="width:149px;">THERMO</td>
			<td style="width:123px;">LC6065</td>
			<td style="width:124px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:281px;">SIGMAFAST&#160;BCIP/NBT</td>
			<td style="width:149px;">Millipore-SIGMA</td>
			<td style="width:123px;">B5655</td>
			<td style="width:124px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:281px;">4-Chloro-1-naphthol</td>
			<td style="width:149px;">Millipore-SIGMA</td>
			<td style="width:123px;">C6788</td>
			<td style="width:124px;"></td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:281px;">Anti-CD63 Antibody (rabbit anti-human) with goat anti-rabbit HRP secondary antibody</td>
			<td style="width:149px;">SYSTEM BIOSCIENCES</td>
			<td style="width:123px;">EXOAB-CD63A-1</td>
			<td style="width:124px;">Primary and secondary antibodies</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:43px;width:281px;">ALB Antibody (F-10)</td>
			<td style="width:149px;">SANTA CRUZ BIOTECHNOLOGY, INC.</td>
			<td style="width:123px;">sc-271605</td>
			<td style="width:124px;">Primary antibody</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:43px;width:281px;">apoB Antibody (C1.4)</td>
			<td style="width:149px;">SANTA CRUZ BIOTECHNOLOGY, INC.</td>
			<td style="width:123px;">sc-13538</td>
			<td style="width:124px;">Primary antibody</td>
		</tr>
		<tr height="41">
			<td height="41" style="height:42px;width:281px;">apoA-I Antibody (B-10)</td>
			<td style="width:149px;">SANTA CRUZ BIOTECHNOLOGY, INC.</td>
			<td style="width:123px;">sc-376818</td>
			<td style="width:124px;">Primary antibody</td>
		</tr>
	</tbody>
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protein digestion, ultrafiltration, and size exclusion chromatography to optimize the isolation of exosomes from human blood plasma and serum

Exosomes, a type of nanovesicle released from all cell types, can be isolated from any bodily fluid. The contents of exosomes, including proteins and RNAs, are unique to the cells from which they are derived and can be used as indicators of disease. Several common enrichment protocols, including ultracentrifugation, yield exosomes laden with soluble protein contaminants. Specifically, we have found that the most abundant proteins within blood often co-purify with exosomes and can confound downstream proteomic studies, thwarting the identification of low abundance biomarker candidates. Of additional concern is irreproducibility of exosome protein quantification due to inconsistent representation of non-exosomal protein levels. The protocol detailed here was developed to remove non-exosomal proteins that co-purify along with exosomes, adding rigor to the exosome purification process. Five methods were compared using paired blood plasma and serum from five donors. Analysis using nanoparticle tracking analysis and micro bicinchoninic acid protein assay revealed that a combined protocol utilizing ultrafiltration and size exclusion chromatography yielded the optimal vesicle enrichment and soluble protein removal. Western blotting was used to verify that the expected abundant blood proteins, including albumin and apolipoproteins, were depleted.

The data presented below were obtained using paired plasma and serum samples from five healthy blood donors. To determine the effects of each processing step, five variations of the presented protocol were performed, and exosome recovery and non-exosome protein removal were compared. The methods trialed included: 1) SEC 700 kDa + Ultrafiltration 3 kDa; 2) Ultrafiltration 100 kDa; 3) Proteinase K + Ultrafiltration 100 kDa; 4) SEC 700 kDa + Ultrafiltration 100 kDa, and 5) Proteinase K + Ult...

Watch this Scientific Journal Video about Protein Digestion, Ultrafiltration, and Size Exclusion Chromatography to Optimize the Isolation of Exosomes from Human Blood Plasma and Serum at JoVE.com

Protein Digestion, Ultrafiltration, and Size Exclusion Chromatography to Optimize the Isolation of Exosomes from Human Blood Plasma and Serum

Here, we present a protocol to purify exosomes from both plasma and serum with reduced co-purification of non-exosomal blood proteins. The optimized protocol includes ultrafiltration, protease treatment, and size exclusion chromatography. Enhanced purification of exosomes benefits downstream analyses, including more accurate quantification of vesicles and proteomic characterization.

Exosomes, a type of nanovesicle released from all cell types, can be isolated from any bodily fluid. The contents of exosomes, including proteins and ...

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