With years of experiences in exosome preparation, Creative Biolabs has developed immunoaffinity capture-based techniques to isolate exosomes with the high purification and homogeneity, from a particular cell type such as tumor cells.

Immunoaffinity

Exosome is a type of membrane vesicles referred to as extracellular vesicles with the diameters ranging from 30 to 150 nm. There are a plenty of proteins and receptors on the membrane of exosomes. This feature of exosomes provides an excellent opportunity to develop highly specific techniques for the isolation of exosomes by tapping on immunoaffinity interactions between those proteins (antigens) and their antibodies, and specific interactions between the receptors and ligands. As a result, immunoaffinity capture-based techniques have been developed for the isolation and purification of exosomes.

Ideally, exosome biomarkers for immunoisolation are membrane-bound, lacking soluble counterparts, and solely expressed or highly concentrated on the surface of exosomes from specific biological sources. Now studies have been identified a number of specific molecular on the surface of exosomes such as CD63, CD81, CD82, CD9, Alix, annexin, EpCAM, and Rab5. Antibodies against these surface markers could be immobilized on a variety of media, including magnetic beads, chromatography matrices, plates, and microfluidic devices for exosome capture. For example, CD34 is a unique biomarker of acute myeloid leukemia (AML) blasts. Antibodies against CD34 can be coated on magnetic microbeads to purify exosomes from plasma of AML patients by means of immunoaffinity interaction between CD34 and their antibodies. This technology is also applied to isolate and purify exosomes derived from a particular cell type such as tumor cells. The advantage of this technology is that it produces pure and homogenous exosomes yields. This approach by design, however, excludes the capture of potentially biologically relevant subpopulations which do not express the particular surface marker of interest.

Fig.1 Detection of CSPG4+ exosomes immunocaptured on beads by flow cytometry. (Sharma, 2018)

Workflow

• Selecting specific surface markers of exosome

  It is very important to confirm the specific molecular on the surface of exosomes derived from particular cell type for immunoaffinity purification of exosome. Based on our experienced and professional technical team and the real-time update of exosomal target molecular database, we can identify the best and most-robust exosomal tags for our clients.

• Designing target-specific antibody

  Creative Biolabs is a leading service provider that focuses on developing high specific, high-affinity antibodies for research, diagnostic and therapeutic use.

• Constructing immobilized media for Immunoaffinity

  Our professional team has developed submicron-size magnetic particles for uses in immunoaffinity capture–magneto-immunocapture. And antibody-coated magnetic particles are effectively capacity to isolate high-purification and high-homogeneity exosomes.

Advantages

• State-of-art technology platform
• Experienced and professional technical team
• Best after-sale service
• High yield and low consumption
• Relatively integrated exosomes

Creative Biolabs has extensive experience in the field of exosome isolation and purification. We are confident to offer the best exosome purification services for global customers based on the immunoaffinity capture-based techniques. With our services, you can attain the high-purity and intact exosomes that will contribute to your downstream analyses, including more accurate quantification of vesicles and proteomic characterization.

If you have any demands in exosome preparation, please don’t hesitate to contact us for more information.

Reference:

1. Sharma, P.; et al. Immunoaffinity-based isolation of melanoma cell-derived exosomes from plasma of patients with melanoma. Journal of Extracellular Vesicles. 2018, 7(1):1435138.

• Exosome Purification via Ultracentrifugation and Microfiltration
• Exosome Purification via Size Exclusion Chromatography (SEC)