The authors sincerely thank Prof. Sarah M. Fortune for kindly sharing M. smegmatis mc2155 stock. They also acknowledge Servier Medical Art (smart.servier.com) for providing some basic elements for Figure 1. They sincerely acknowledge the support of the rest of the lab members for their patient adjustments during the long use of the incubator shakers, centrifuges, and ultracentrifuges for mEV enrichment. They also acknowledge Mr. Surjeet Yadav, the laboratory assistant, for always making sure the necessary glassware and consumables were always available and handy. Lastly, they acknowledge the administrative, the purchase, and the finance teams of THSTI for their constant support and help in the seamless execution of the project.

1. Growth conditions of Mycobacterium smegmatis, Escherichia coli, and their derivatives
<ol>
	<li>Media
	<ol>
		<li>Middlebrook 7H9 liquid broth
		<ol>
			<li>Prepare 20% Tween-80 stock solution by pre-warming the required volume of double-distilled water (ddw) in a glass beaker to ~45-50 oC in a microwave, add the required volume of Tween-80 using an appropriate measuring cylinder, and stir continuously on a small magnetic stirrer to bri...

Since developing a novel TB vaccine that is superior to and can replace BCG remains a formidable challenge, as an alternative, several groups are pursuing the discovery of different subunit TB vaccines that can boost BCG&#39;s potency and extend its protective duration48,49. Given the increasing attention to bacterial EVs (bEVs) as potential subunits and as natural adjuvants50,51, consistent enrichment of...

An erratum was issued for:&#160;<a href="https://www.jove.com/t/65138">Enrichment of Native and Recombinant Extracellular Vesicles of Mycobacteria</a>. The Authors section was updated from:
Praapti Jayaswal1 
Mohd Ilyas1 
Kuljit Singh1,2 
Saurabh Kumar1,3 
Lovely Sisodiya1 
Sapna Jain1 
Rahul Mahlawat1 
Nishant Sharma1 
Vishal Gupta1 
Krishnamohan Atmakuri1 
1Bacterial Pathogenesis Laboratory, Infectious Diseases and Immunology Group, Translational Health Science and Technology Institute, NCR Biotech Science Cluster 
2Clinical Microbiology Division, CSIR-Indian Institute of Integrative Medicine 
3ICAR-Research Complex for Eastern Region 
4Public Health Research Institute, Rutgers University
to:
Praapti Jayaswal1 
Mohd Ilyas1 
Kuljit Singh1,2 
Saurabh Kumar1,3 
Lovely Sisodiya1 
Sapna Jain1 
Rahul Mahlawat1 
Nishant Sharma1,4 
Vishal Gupta1 
Krishnamohan Atmakuri1 
1Bacterial Pathogenesis Laboratory, Infectious Diseases and Immunology Group, Translational Health Science and Technology Institute, NCR Biotech Science Cluster 
2Clinical Microbiology Division, CSIR-Indian Institute of Integrative Medicine 
3ICAR-Research Complex for Eastern Region 
4Public Health Research Institute, Rutgers University

An erratum was issued for:&#160;<a href="https://www.jove.com/t/65138">Enrichment of Native and Recombinant Extracellular Vesicles of Mycobacteria</a>. The Authors section was updated.

Erratum: Enrichment of Native and Recombinant Extracellular Vesicles of Mycobacteria

Despite the development and administration of a wide range of vaccines against infectious diseases, even to this day, ~30% of all human deaths still occur from communicable diseases1. Before the advent of the Tuberculosis (TB) vaccine - Bacillus Calmette Guerin (BCG) - TB was the number one killer (~10,000 to 15,000/100,000 population)2. With the administration of BCG and easy access to first and second-line anti-TB drugs, by 2022, TB-related deaths have dramatically dropped to ~1 million/year by 2022 (i.e., ~15-20/100,000 population1). However, in TB endemic populations of the world, TB-related deaths continue to stand at ~100-550/100,000 population1. While experts recognize several reasons leading to these skewed numbers, BCG-mediated protection not lasting for even the first decade of life appears to be the prominent reason3,4,5,6,7. Consequently, given the renewed &#39;Sustainable Development Goals&#39; of the UN and the &#39;End TB Strategy&#39;, of WHO, there is a concerted global effort to develop a much superior vaccine alternative to BCG that perhaps provides lifelong protection from TB.

Towards that objective, several groups are currently evaluating modified/recombinant BCG strains, non-pathogenic and attenuated mycobacterial species other than BCG, and subunit candidates8,9,10,11,12,13,14,15,16,17,18. Typically, subunit vaccines are liposomes selectively loaded with few purified (~1-6) full-length or truncated immunogenic proteins of the pathogen. However, because of their spurious folding into non-native conformations and/or random non-functional interactions between the loaded proteins, subunits often lack native and germane epitopes and hence, fail to sufficiently prime the immune system14,19,20.

Consequently, extracellular vesicles (EVs) of bacteria have picked up pace as a promising alternative21,22,23,24,25,26. Typically, bacterial EVs (bEVs) contain a subset of their cellular components, including some portions of nucleic acids, lipids, and hundreds of metabolites and proteins27,28. Unlike liposomes where a few purified proteins are artificially loaded, bEVs contain hundreds of naturally-loaded, natively-folded proteins with a better propensity to prime the immune system, especially without the boost/aid of adjuvants and Toll-like receptor (TLR) agonists27,28,29. It is in this line of research that we and others have explored the utility of mycobacterial EVs as potential subunit boosters to BCG30. Despite concerns that bEVs lack uniform antigen loads, EVs from attenuated Neisseria meningitidis have successfully protected humans against serogroup B meningococcus31,32.
At least theoretically, the best EVs that could boost BCG well are the EVs enriched from pathogenic bacteria. However, enriching EVs generated by pathogenic mycobacterium is expensive, time-consuming, and risky. Additionally, pathogen-generated EVs may be more virulent than protective. Given the potential risks, here, we report a well-tested protocol for the enrichment of EVs generated by axenically grown Msm, an avirulent mycobacterium.
However, despite encoding several pathogen protein orthologs, avirulent mycobacteria lack several vaccine antigens/pathogenic protein epitopes necessary to sufficiently prime the immune system towards protection33. Therefore, we also explored constructing and enriching recombinant EVs of Msm through molecular engineering, such that a significant portion of any pathogenic protein of interest expressed and translated in Msm, must reach its EVs. We hypothesized that one or more of the top 10 abundant proteins of Msm EVs when fused to the protein of interest will aid in such translocation.
While we were beginning to standardize the enrichment of mycobacterial EVs (mEVs) in our laboratory, in 2011, Prados-Rosales et al. first reported the visualization and enrichment of mEVs in vitro30. Later, in 2014, the same group published a modified version of their 2011 method34. In 2015, Lee et al. also reported an independently standardized method for mEV enrichment again from axenic cultures of mycobacteria35. Combining both protocols34,35 and incorporating a few of our modifications after thorough standardization, we describe here a protocol that helps routinely enrich mEVs from axenic cultures of mycobacteria36.
Here, we particularly detail the enrichment of Msm-specific EVs, which is an extension of a published protocol36 for the enrichment of mycobacterial EVs in general. We also detail how to construct recombinant mEVs (R-mEVs) that contain the mCherry protein (as a red fluorescent reporter) and EsxA (Esat-6)37,38,39 a predominant immunogen and a potential subunit vaccinogen of Mycobacterium tuberculosis. The protocol for enriching the R-mEVs remains identical to the one we have described for enriching native EVs from Msm.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>A2 type Biosafety Cabinet</td>
			<td>Thermo Fisher Scientific, USA</td>
			<td></td>
			<td>1300 series</td>
		</tr>
		<tr>
			<td>Bench top Centrifuge</td>
			<td>Eppendorf, USA</td>
			<td></td>
			<td>5810 R</td>
		</tr>
		<tr>
			<td>BstB1, HindIII, HpaI</td>
			<td>NEB, USA</td>
			<td></td>
			<td>NEB</td>
		</tr>
		<tr>
			<td>Cell densitometer</td>
			<td>GE Healthcare, USA</td>
			<td></td>
			<td>Ultraspec 10</td>
		</tr>
		<tr>
			<td>Citric Acid</td>
			<td>Sigma-Aldrich, Merck, USA</td>
			<td></td>
			<td>Sigma Aldrich</td>
		</tr>
		<tr>
			<td>Dibasic Potassium Phosphate</td>
			<td>Sigma-Aldrich, Merck, USA</td>
			<td></td>
			<td>Sigma Aldrich</td>
		</tr>
		<tr>
			<td>Double Distilled Water</td>
			<td>Merck, USA</td>
			<td></td>
			<td>~18.2 MW/cm @ 25 oC</td>
		</tr>
		<tr>
			<td>Electroporation cuvettes</td>
			<td>Bio-Rad, USA</td>
			<td></td>
			<td>2 mm</td>
		</tr>
		<tr>
			<td>Electroporator</td>
			<td>Bio-Rad, USA</td>
			<td></td>
			<td>Electroporator</td>
		</tr>
		<tr>
			<td>EsxA-specific Ab</td>
			<td>Abcam, UK</td>
			<td></td>
			<td>Rabbit polyclonal</td>
		</tr>
		<tr>
			<td>Ferric Ammonium Citrate</td>
			<td>Sigma-Aldrich, Merck, USA</td>
			<td></td>
			<td>Sigma Aldrich</td>
		</tr>
		<tr>
			<td>Floor model centrifuge</td>
			<td>Thermo Fisher Scientific, USA</td>
			<td></td>
			<td>Sorvall RC6 plus</td>
		</tr>
		<tr>
			<td>Glassware</td>
			<td>Borosil, INDIA</td>
			<td></td>
			<td>1 L Erlenmeyer flasks</td>
		</tr>
		<tr>
			<td>Glycerol</td>
			<td>Sigma-Aldrich, Merck, USA</td>
			<td></td>
			<td>Sigma Aldrich</td>
		</tr>
		<tr>
			<td>HEPES and Sodium Chloride</td>
			<td>Sigma-Aldrich, Merck, USA</td>
			<td></td>
			<td>Sigma Aldrich</td>
		</tr>
		<tr>
			<td>Incubator shakers</td>
			<td>Thermo Fisher Scientific, USA</td>
			<td></td>
			<td>MaxQ 6000 &#38; 8000</td>
		</tr>
		<tr>
			<td>L-Asparagine</td>
			<td>Sigma-Aldrich, Merck, USA</td>
			<td></td>
			<td>Sigma Aldrich</td>
		</tr>
		<tr>
			<td>Luria Bertani Broth and Agar, Miller</td>
			<td>Hi Media, INDIA</td>
			<td></td>
			<td>Hi Media</td>
		</tr>
		<tr>
			<td>Magnesium Sulfate Heptahydrate</td>
			<td>Sigma-Aldrich, Merck, USA</td>
			<td></td>
			<td>Sigma Aldrich</td>
		</tr>
		<tr>
			<td>Magnetic stirrer</td>
			<td>Tarsons, INDIA</td>
			<td></td>
			<td>Tarsons</td>
		</tr>
		<tr>
			<td>mCherry-specific Ab</td>
			<td>Abcam, UK</td>
			<td></td>
			<td>Rabbit monoclonal</td>
		</tr>
		<tr>
			<td>Microwave</td>
			<td>LG, INDIA</td>
			<td></td>
			<td>MC3286BLT</td>
		</tr>
		<tr>
			<td>Middlebrook 7H9 Broth</td>
			<td>BD, USA</td>
			<td></td>
			<td>Difco Middlebrook 7H9 Broth</td>
		</tr>
		<tr>
			<td>Middlebrook ADC enrichment</td>
			<td>BD, USA</td>
			<td></td>
			<td>BBL Middlebrook ADC enrichment</td>
		</tr>
		<tr>
			<td>Nanodrop</td>
			<td>Thermo Fisher Scientific, USA</td>
			<td></td>
			<td>Spectronic 200 UV-Vis</td>
		</tr>
		<tr>
			<td>NEB5a</td>
			<td>NEB, USA</td>
			<td></td>
			<td>a derivative of DH5a</td>
		</tr>
		<tr>
			<td>Optiprep (Iodixanol)</td>
			<td>Merck, USA</td>
			<td></td>
			<td>Available as 60% stock solution (in water)</td>
		</tr>
		<tr>
			<td>PCR purification kit</td>
			<td>Hi Media, INDIA</td>
			<td></td>
			<td>Hi Media</td>
		</tr>
		<tr>
			<td>pH Meter</td>
			<td>Mettler Toledo, USA</td>
			<td></td>
			<td>Mettler Toledo</td>
		</tr>
		<tr>
			<td>Plasmid DNA mini kit</td>
			<td>Hi Media, INDIA</td>
			<td></td>
			<td>Hi Media</td>
		</tr>
		<tr>
			<td>Plate incubator</td>
			<td>Thermo Fisher Scientific, USA</td>
			<td></td>
			<td>New Series</td>
		</tr>
		<tr>
			<td>Plasmid pMV261</td>
			<td>Addgene, USA * 
			*The&#160;&#160; plasmid&#160;&#160; is&#160;&#160; no&#160;&#160; more available in this plasmid bank</td>
			<td></td>
			<td>Shuttle vector</td>
		</tr>
		<tr>
			<td>Proof-reading DNA Polymerase</td>
			<td>Thermo Fisher Scientific, USA</td>
			<td></td>
			<td>Phusion DNA Plus Polymerase</td>
		</tr>
		<tr>
			<td>Q5 Proof-reading DNA Polymerase</td>
			<td>NEB, USA</td>
			<td></td>
			<td>NEB</td>
		</tr>
		<tr>
			<td>Refrigerated circulating water bath</td>
			<td>Thermo Fisher Scientific, USA</td>
			<td></td>
			<td>R20</td>
		</tr>
		<tr>
			<td>Middlebrock 7H11 Agar base</td>
			<td>BD, USA</td>
			<td></td>
			<td>BBL Seven H11 Agar base</td>
		</tr>
		<tr>
			<td>SOC broth</td>
			<td>Hi Media, INDIA</td>
			<td></td>
			<td>Hi Media</td>
		</tr>
		<tr>
			<td>Sodium Hydroxide</td>
			<td>Sigma-Aldrich, Merck, USA</td>
			<td></td>
			<td>Sigma Aldrich</td>
		</tr>
		<tr>
			<td>T4 DNA Ligase</td>
			<td>NEB, USA</td>
			<td></td>
			<td>NEB</td>
		</tr>
		<tr>
			<td>Tween-80</td>
			<td>Sigma-Aldrich, Merck, USA</td>
			<td></td>
			<td>Sigma Aldrich</td>
		</tr>
		<tr>
			<td>Ultracentrifuge</td>
			<td>Beckman Coulter, USA</td>
			<td></td>
			<td>Optima L100K</td>
		</tr>
		<tr>
			<td>Ultracentrifuge tubes - 14 mL</td>
			<td>Beckman Coulter, USA</td>
			<td></td>
			<td>Polyallomer type &#8211; ultra clear type in SW40Ti rotor</td>
		</tr>
		<tr>
			<td>Ultracentrifuge tubes - 38 mL</td>
			<td>Beckman Coulter, USA</td>
			<td></td>
			<td>Polypropylene type&#8211; cloudy type for SW28 rotor</td>
		</tr>
		<tr>
			<td>Ultrasonics cleaning waterbath sonicator</td>
			<td>Thermo Fisher Scientific, USA</td>
			<td></td>
			<td>Sonicator - bench top model</td>
		</tr>
		<tr>
			<td>0.22 &#181;m Disposable filters</td>
			<td>Thermo Fisher Scientific, USA</td>
			<td></td>
			<td>Nunc-Nalgene</td>
		</tr>
		<tr>
			<td>30-kDa Centricon concentrators</td>
			<td>Merck, USA</td>
			<td></td>
			<td>Amicon Ultra centrifugal filters - Millipore</td>
		</tr>
		<tr>
			<td>3X FLAG antibody</td>
			<td>Sigma-Aldrich, Merck, USA</td>
			<td></td>
			<td>Sigma Aldrich</td>
		</tr>
		<tr>
			<td>400 mL Centrifuge bottles</td>
			<td>Thermo Fisher Scientific, USA</td>
			<td></td>
			<td>Nunc-Nalgene</td>
		</tr>
		<tr>
			<td>50 mL Centrifuge tubes</td>
			<td>Corning, USA</td>
			<td></td>
			<td>Sterile, pre-packed</td>
		</tr>
		<tr>
			<td>Bacteria</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Strain</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Escherichia coli</td>
			<td>NEB, USA</td>
			<td></td>
			<td>NEB 5-alpha (a derivative of DH5&#945;).</td>
		</tr>
		<tr>
			<td>Msm expressing cfp29::mCherry</td>
			<td>This study</td>
			<td></td>
			<td>MC2&#160;155</td>
		</tr>
		<tr>
			<td>Msm expressing cfp29::esxA</td>
			<td>This study</td>
			<td></td>
			<td>MC2&#160;155</td>
		</tr>
		<tr>
			<td>Msm expressing cfp29::esxA::3X FLAG</td>
			<td>This study</td>
			<td></td>
			<td>MC2&#160;155</td>
		</tr>
		<tr>
			<td>Mycobacterium smegmatis (Msm)</td>
			<td>Prof. Sarah M. Fortune, Harvard Univ, USA</td>
			<td></td>
			<td>&#160;MC2&#160;155</td>
		</tr>
	</tbody>
</table>

enrichment of native and recombinant extracellular vesicles of mycobacteria

Most bacteria, including mycobacteria, generate extracellular vesicles (EVs). Since bacterial EVs (bEVs) contain a subset of cellular components, including metabolites, lipids, proteins, and nucleic acids, several groups have evaluated either the native or recombinant versions of bEVs for their protective potency as subunit vaccine candidates. Unlike native EVs, recombinant EVs are molecularly engineered to contain one or more immunogens of interest. Over the last decade, different groups have explored diverse approaches for generating recombinant bEVs. However, here, we report the design, construction, and enrichment of recombinant mycobacterial EVs (mEVs) in mycobacteria. Towards that, we use Mycobacterium smegmatis (Msm), an avirulent soil mycobacterium as the model system. We first describe the generation and enrichment of native EVs of Msm. Then, we describe the design and construction of recombinant mEVs that contain either mCherry, a red fluorescent reporter protein, or EsxA (Esat-6), a prominent immunogen of Mycobacterium tuberculosis. We achieve this by separately fusing mCherry and EsxA N-termini with the C-terminus of a small Msm protein Cfp-29. Cfp-29 is one of the few abundantly present proteins of MsmEVs. The protocol to generate and enrich recombinant mEVs from Msm remains identical to the generation and enrichment of native EVs of Msm.

We use M. smegmatis (Msm) as the model mycobacterium to demonstrate the enrichment of both native and recombinant mEVs (R-mEVs). This schematically summarized mEVs enrichment protocol (Figure 1) also works for the enrichment of R-mEVs of Msm and native EVs of Mtb (with minor modifications as in protocol notes of 1.2). Visualization of the enriched mEVs requires negatively staining them under a transmission electron microscope36 (Figure 2A...

Watch this Scientific Journal Video about Enrichment of Native and Recombinant Extracellular Vesicles of Mycobacteria at JoVE.com

Enrichment of Native and Recombinant Extracellular Vesicles of Mycobacteria

This protocol details the enrichment of native mycobacterial extracellular vesicles (mEVs) from axenic cultures of Mycobacterium smegmatis (Msm) and how mCherry (a red fluorescent reporter)-containing recombinant MsmEVs can be designed and enriched. Lastly, it verifies the novel approach with the enrichment of MsmEVs containing the EsxA protein of Mycobacterium tuberculosis.

Most bacteria, including mycobacteria, generate extracellular vesicles (EVs). Since bacterial EVs (bEVs) contain a subset of cellular components, ...

Enriching mycobacterial EVs helps delineate their contents, decipher their factions, and dates designing ways to construct and generate recombinant EVs that mainly exploit vaccine candidates. Six series generate from different locations of the bacterial surface. They do not have conserved markers.Hence, any affinity-based approaches can enrich only a subset of the EVs. In contrast, our method captures all generated mycobacteria EVs. Demonstrating the procedure will be Mohd Ilyas, a PHD student from my laboratory.To begin, add one milliliter of glycerol stock of wild-type or recombinant Mycobacterium smegmatis to a 50-milliliter centrifuge tube containing 10 milliliters of pre-warmed 7H9 broth. Close the lid and swirl the tube before incubating the culture overnight at 37 degrees Celsius in between 200 to 220 RPM. On the next day, when the optical density at 600 nanometers reaches approximately one, centrifuge the culture at 3, 200 G for 10 minutes at room temperature and discard the supernatant into a liquid discard container.Add one milliliter of pre-warmed Sautons media and gently resuspend to obtain a uniform suspension. Make up the volume to 10 milliliters using Sautons media. Centrifuge again and discard the supernatant.After washing, resuspend the bacterial cells. in 20 milliliters of pre-warmed Sautons media and measure the optical density at 600 nanometers. Inoculate the required volume of bacterial suspension into a one to two liter Erlenmeyer flask containing 330 milliliters of Sautons media and incubate at 37 degrees Celsius in 200 RPM until the optical density reaches 0.3.On the next day, wash the cells once as previously demonstrated and resuspend the pellet in 330 milliliters of Sautons containing 1/10 Tween 80. Distribute 50 milliliters of the cell suspension into six one-liter flasks, each containing 280 milliliters of pre-warmed Sautons containing 1/10 Tween 80. Incubate the cultures at 37 degrees Celsius in 200 RPM until the optical density reaches two to 2.5.Add two liters of mid-exponential stage cultures to six 400-milliliter bottles and centrifuge at 8, 000 G for 20 minutes at four degrees Celsius. Collect the supernatant and pre-chilled autoclaved flasks or beakers and store an aliquot of the pellet for analytical procedures. The pellet is colored if the EVs are recombinant for mCherry and brown if they are wild-type or recombinant for non-fluorescent proteins.Filter the culture supernatant through a 0.45-micron disposal filter, followed by filtration through a 0.22-micron filter to remove all traces of bacteria. Next, pre-wash the 30-kilodalton membrane concentrators with 15 milliliters of double-distilled water at 4, 000 G for 20 minutes at four degrees Celsius. Then wash with 15 milliliters of pre-filtered cold Sautons media using the same conditions to remove all traces of chemicals.After washing, add 15 milliliters of filtered cultured supernatant into a concentrator and concentrate at 4, 000 G for 20 minutes at four degrees Celsius. Transfer the concentrate to a cold 40-milliliter Oak Ridge centrifuge tube or a 50-milliliter fresh Falcon centrifuge tube. Once the entire two liters of culture filtrate is concentrated, transfer the concentrate into a double distilled, washed, and pre-chilled 50-milliliter polypropylene centrifuge tube and subjected to a two-step centrifugation.First at 4, 000 G, and then at 15, 000 G.Transfer the centrifuged concentrate into a pre-chilled 38.5-milliliter ultracentrifuge tube and spin at 100, 000 G for four hours at four degrees Celsius. Collect the supernatant in a pre-chilled 50 milliliter fresh Falcon centrifuge tube. invert the ultracentrifuge tube on a fresh, lint-free absorbent paper to remove traces of the supernatant and resuspend the pellet in 600 microliters of HEPES buffer.Layer the resuspended pellet at the bottom of a 13-milliliter pre-chilled UltraClear polypropylene ultracentrifuge tube and gently mix with four milliliters of inert 60%density gradient iodixanol solution. Then overlay with one milliliter each of 40%30%20%and 10%of iodixanol. Fill the tube by adding four milliliters of 6%iodixanol at the top.After carefully weighing the tube in a glass beaker or a stand, gently transfer it into the swinging buckets and then to the swinging buckets rotor for ultracentrifugation at 141, 000 G for 16 hours at four degrees Celsius. After ultracentrifugation, carefully remove the tube and collect a one milliliter fraction into autoclaved microcentrifuge tubes. TEM analysis showed a mycobacterial EVs are circular and nano-tracking analysis confirmed different sized EVs with diameters ranging between 20 and 250 nanometers.When the N-terminal end of mCherry was translationally fused to the C-terminal end of CFP-29, a portion of enriched mEVs of Msm turned pink, indicating cf-29's ability to carry a foreign protein of interest. CFP-29 was then used to evaluate EsxA delivery into Msm EVs. Mtb's EsxA was observed in Msm EVs in low quantities.CFP-29 EsxA 3X FLAG was more stable and accumulated at higher levels in mEVs. Enriching the EVs from mycobacteria grown under physiological different conditions provides insights into their altered contents and modified functions that dictate sustained infectivity, pathogenesis, and pathogen spread.

enrichment-native-recombinant-extracellular-vesicles

Research

JoVE Journal

Immunology and Infection

753 vistas.  NCR Biotech Science Cluster. El enriquecimiento de las VE micobacterianas ayuda a delinear su contenido, descifrar sus facciones y fechas, diseñando formas de construir y generar VE recombinantes que exploten principalmente las vacunas candidatas. Seis series se generan a partir de diferentes ubicaciones de la superficie bacteriana. No tienen marcadores conservados.Por lo tanto, cualquier enfoque basado en la afinidad puede enriquecer solo un subconjunto de los EV. Por el contrario, nuestro método captura todas ...