Exosome Research

EV-Save™ Extracellular Vesicle Blocking Reagent is a polymer reagent to prevent adsorbing extracellular vesicles in cell culture supernatants to laboratory tools such as tubes and pipet tips, which reduces the loss of extracellular vesicles during experiments and storage. Add into samples before ultrafiltration of cell culture supernatants, isolation and storage of extracellular vesicles.

Precautions for use
  • The effect of EV-Save™ cannot be obtained when it is used for serum, plasma, or samples containing a lot of impurities.
  • The product contains a polymer. Do not use EV-Save™ if the polymer may affect the experimental results in the post process.
    It have been confirmed that there are no effect by EV-Save™ in the following analyses using extracellular vesicles.
    1. Nanoparticle Tracking Analysis
    2. Western blot
    3. ELISA
    4. Microarray analysis
    5. Cell culture

Application of the PS affinity method to ELISA

　　We developed PS Capture™ Exosome ELISA Kit by applying affinity binding of Tim4 protein with exosomes. This kit is capable of detecting exosomes at a sensitivity higher than that of conventional ELISA methods immobilization of antibodies against exosome surface markers. Exosomes in samples such as culture supernatants and serum are captured by Tim4 protein on adry plate in the presence of calcium ion. The captured exosomes are detected by a primary antibody against an exosome surface marker protein and a labeled secondary antibody. While a mouse anti-CD63 monoclonal antibody is provided with the kit, a user-provided mouse primary antibody against any other exosome surface marker may also be used for exosome detection.

　　　

PS Capture™ Exosome Flow Cytometry Kit

Features

  • High-Sensitive Qualitative Analysis
  • Easy Operation by Magnetic Beads
  • Direct Detection without Purification
  • Total 3 hours ~ from Isolation to Staining ~

 

A new method for exosome purification using phosphatidylserine and Tim4

The exosome membrane contains proteins and lipids derived from secretory cells. Among those components, phosphatidylserine (PS) is known to be oriented inside the cell membrane of intact cells by the enzymatic activity of lipid flippase, and be known to be exposed also on the outer surface of exosome membrane3). In addition, T-cell immunoglobulin domain and mucin domain-containing protein 4 (Tim4), the receptor involved in phagocytosis of apoptotic cells by macrophages, is known to bind PS via the IgV domain located within the extracellular region in a calcium ion-dependent manner.4)

Based on these findings, we developed a new and unprecedented method for exosome purification using Tim4-immobilized magnetic beads (capable of capturing exosomes in samples such as culture supernatants and serum in the presence of calcium ions and releasing them by elution with a buffer supplemented with a chelating reagent) in collaboration with Professor Rikinari Hanayama (Department of Immunology, Kanazawa University Graduate School of Medical Sciences) and successfully constructed an exosome purification kit based on these magnetic beads5).

This exosome purification kit, MagCapture™ Exosome Isolation Kit PS, has realized easy purification of intact exosomes with higher purity than that obtained by any conventional methods for exosome purification. It is currently being established as a new exosome purification method replacing ultracentrifugation, the conventional gold standard.

 

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