Overview

Eavesdrop on the EV “surfeome”

Take advantage of powerful LC/MS proteomics approaches to study the biology of surface-associated extracellular vesicle (EV) proteins (the surfeome) and to identify EV surface biomarkers using SBI’s ExoMSTM Surface Protein Capture Kit (Serum/Plasma). The kit provides a fast, well-validated, and robust method for selectively capturing surface and membrane-associated proteins from EVs that have already been isolated from serum or plasma, enabling proteomics studies of this important subset of EV proteins. Because of the low residual protein carryover delivered by this kit, you get increased detection of low-abundance biomarkers that are often missed using traditional approaches.

Ensure that your exosomes are telling you everything with SBI’s ExoMSTM Surface Protein Capture Kit (Serum/Plasma).

• Unique—the only commercially available kit that specifically captures exosome surface and membrane proteins• Sensitive—removes many common contaminants from EV preps, such as albumin and IgG, for improved biomarker detection by LC/MS• Compatible—works with EVs isolated using a variety of methods including ExoQuick^®, ExoQuick^® PLUS, ultracentrifugation, and most column-based kits sold by other vendors• Fast—go from isolated sample to LC/MS in less than 5 hours• Flexible—choose this kit for exosomes isolated from serum or plasma, the ExoMS Surface Protein Capture Kit (Tissue Culture) for exosomes isolated from tissue culture or other biofluids, or the ExoMS Total Protein Capture Kit to isolate all EV proteins from exosomes isolated from any biofluid

How It Works

Delivering sensitive protein detection through reduced protein carryover

Our robust surface and membrane protein capture technology is based on a two-step biotinylation and bead capture method that efficiently sequesters surface and membrane proteins away from internal EV proteins. The result is a protein preparation significantly enriched in membrane-associated proteins (Figure 1).

Figure 1. Membrane-associated proteins are enriched in human serum EV samples processed with the ExoMS Surface Protein Capture Kit compared to samples processed with the ExoMS Total Protein Capture Kit.

In addition, the ExoMS Surface Protein Capture Kit is able to deliver sensitive biomarker detection through the use of a proprietary, affinity-based resin that traps many of the carryover-proteins commonly co-isolated with EVs, but which are not actually carried in or on the surface of EVs (Figure 2). Reduction of these protein contaminants, such as albumin and IgG, reduces their strong signal during mass spec analysis, enabling improved detection of more relevant but lower-abundance proteins.

Figure 2. Common carryover proteins are reduced in human serum EV samples processed with the ExoMS Kit compared to samples processed using a standard protocol.

Supporting Data

Proteins identified from an ExoMS Surface Protein Capture Kit-prepared sample

See the 25 most abundant membrane-associated proteins identified by LC/MS from a human serum EV sample prepared with the ExoMS Surface Protein Capture Kit. Highlighted entries are proteins which were identified from a sample prepared using the ExoMS Surface Protein Capture Kit and not detected in comparable MS analysis of total EV protein from isolated exosomes, demonstrating the enhanced sensitivity and capability provided by the ExoMS kit for detecting surface and membrane-associated EV proteins.

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