ExoTrap™ Exosome Isolation Spin Column Kit for protein research

 

User Report

Yoshitaka Sato

Department of Virology, Nagoya University Graduate School of Medicine

Products

  • ●ExoTrap™ Exosome Isolation Spin Column Kit for Protein Research （Cat.No. SHI-EXO-K010）
Products Page

Experimental findings

Exosomes are membrane-enclosed vesicles of 30 to 100 nm containing proteins and nucleic acids and are secreted by various cells. By gaining access to the circulation, they may transmit signals to cells at distant locations. It has been observed that intercellular communication via exosomes is associated with antigen presentation, apoptosis, inflammation, tumor progression and malignant transformation. It is expected that exosomes will be important in various fields, such as in the development of drug delivery systems.

We are interested in the interaction between virus-infected cells and nearby non-infected cells. When virally infected cells are mixed and cultured with non-infected cells, fluorescent immunostaining can detect viral proteins in non-infected cells, appearing as punctate signals. From this observation, I became interested in exosomes as mediators of intercellular communication.

Comparison of exosomes recovered from various sources and under different conditions is challenging because of the lengthy and difficult methods involved, classically including ultracentrifugation. Therefore, from the viewpoint of operation ease (anybody can purify), purification time (purification can be done in a short time), and application versatility (exosomes themselves, as well as included proteins and nucleic acids can be analyzed), we explored commercially available exosome purification kits and found CosmoBio USA’s “ExoTrap™ Exosome Isolation Spin Column Kit” to be the ideal purification solution.

The greatest advantage of ExoTrap™ is that exosomes can be purified from small amounts of sample in "a short time" of only 30 minutes. As an exosome research beginner, ExoTrap™ allowed me to detect by western blot viral proteins associated with exosomes that could not be detected in the pre-purification culture supernatant. Also, I was able to show that viral proteins were not detected in ExoTrap™-purified exosomes recovered from culture supernatants of exosome inhibitor (GW4869)-treated cells(1). Although ExoTrap™ may not be suitable for inexpensively purifying large amounts of exosomes, it is highly recommended for rapid and easy purification of exosomes from small volumes.

Figures

Figure 1. Western blot before and after exosome purification and before and after treatment with exosome inhibitor

(A) Western blot showing LMP1 and Hsp70 expression in “ExoTrap™ Exosome Isolation Spin Column Kit”-purified exosomes. (B) Western blot showing LMP1 and Hsp70 expression in “ExoTrap™ Exosome Isolation Spin Column Kit”-purified exosomes from cell culture supernatants treated or not with exosome inhibitor (GW4869).