Membrane Vesicle Separation
Membrane Vesicle Separation - Related Videos
04:51
Size Exclusion Chromatography Based Separation of Bacterial Extracellular Vesicles: A Technique to Separate Heterogenous Population of Gram-Negative Bacterial Outer Membrane Vesicles Based on Their Size
0 Views •
2025
In this video, we demonstrate a technique–size exclusion chromatography–to separate a heterogenous population of outer membrane vesicles or OMVs derived from bacteria. These vesicles are nanosized spherical structures and are separated into large and small subpopulations based on their size through Size Exclusion Chromatography.
03:47
Separation of Inner and Outer Membrane Fractions of Gram-Negative Bacteria
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2025
Source: Cian, M. B. et. al., Separation of the Cell Envelope for Gram-negative Bacteria into Inner and Outer Membrane Fractions with Technical Adjustments for Acinetobacter baumannii. J. Vis. Exp. (2020)This video demonstrates the separation of the inner and outer membrane fractions of Gram-negative bacteria using sucrose gradient ultracentrifugation. The membrane fractions are purified and stored at low temperatures for targeted analysis of membrane-specific components.
03:15
Separation and Enrichment of Extracellular Vesicles in the Presence of Virions
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2026
Source: DeMarino, C., et al. Purification of High Yield Extracellular Vesicle Preparations Away from Virus. J. Vis. Exp. (2019)The video demonstrates the separation of EVs from virions and other contaminants by density gradient centrifugation, followed by capture and concentration with hydrogel nanoparticles. Washed fractions are then ready for downstream identification of those enriched in EVs.
06:26
Pulling Membrane Nanotubes from Giant Unilamellar Vesicles
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Cited by 42 •
2017
Many proteins in the cell sense and induce membrane curvature. We describe a method to pull membrane nanotubes from lipid vesicles to study the interaction of proteins or any curvature-active molecule with curved membranes in vitro.
03:20
Generating Plasma Membrane Vesicles from Bone Marrow Stem Cells
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2025
This video demonstrates a method to generate plasma membrane vesicles from bone marrow stem cells by passing them rapidly through a membrane filter. These PMVs show potential for cytoplasm replacement therapy.
FAQs
Ultracentrifugation separates particles according to their sedimentation behavior, which depends on factors such as applied centrifugal force and the composition of the surrounding medium. Vesicles and contaminants therefore move through the medium at different rates or collect in different fractions. Controlling these conditions improves recovery of vesicle-enriched material while limiting co-sedimenting proteins and other particles.
Size-exclusion chromatography uses porous beads to separate components by how readily they enter the bead structure. Larger vesicles and smaller soluble molecules pass through different pathways and emerge in separate fractions. This mechanism provides an alternative to sedimentation-based separation and can help reduce protein contamination when the sample contains both membrane vesicles and soluble biological material.
Centrifugation force, medium composition, filtration, and fraction collection all influence separation quality. Force and medium composition affect how particles sediment, whereas filtration can limit unwanted material before or during processing. Collecting fractions carefully is also important because neighboring fractions may contain different mixtures. Together, these controls help preserve vesicle-rich material and reduce contamination.
Some separation approaches exploit differences in how vesicle surfaces interact with the surrounding medium or separation material. These interactions can distinguish vesicles from proteins or other particles that behave differently at the surface. Their usefulness depends on maintaining suitable medium conditions and collecting the appropriate fractions, because altered interactions can change which components remain together or separate.
A typical workflow begins with a complex biological sample, followed by a separation step selected for differences in size, density, buoyant mass, or surface interactions. Filtration and controlled medium composition can help limit unwanted material, while centrifugation or porous-bead chromatography resolves components. Researchers then collect relevant fractions and characterize them to assess vesicle enrichment and contamination.
The choice depends on which physical difference best distinguishes the vesicles from unwanted components. Centrifugation is appropriate when sedimentation behavior, density, or buoyant mass provides useful separation. Size-exclusion chromatography is useful when passage through porous beads can resolve vesicles from differently sized components, particularly soluble proteins. The sample composition and desired fraction therefore guide method selection.
Researchers characterize the collected fractions to confirm that separation produced the intended sample composition. Evaluation focuses on whether vesicle-rich material was obtained and whether proteins or other particles remain as contaminants. Comparing fraction composition with the experimental objective helps determine whether force, medium, filtration, or collection conditions require adjustment before downstream biological analysis.
Purified fractions support studies of extracellular communication and membrane trafficking by providing material whose physical and molecular properties can be examined. They also contribute to biomarker research and investigations of vesicle-based therapeutic delivery. In each case, reducing contaminating proteins and particles is important because impurities can obscure vesicle-associated signals or complicate interpretation of biological effects.