Since the discovery of exosomes, their potential diagnostic value has been the focus of considerable research. However, the lack of a rapid and simple technique for the quantitative analysis of exosomes greatly limits the application of exosomes in clinical research. In this study, Zhejiang University researchers describe a newly developed one-step chemiluminescence immunoassay for the rapid quantitative analysis of exosomes from biofluids. Their new technique, named ExoNANO, adopts a double-antibody sandwich strategy using anti-CD63 antibody-conjugated superparamagnetic iron oxide particles (SIOPs) and acridinium ester (ACE)-labeled anti-CD9 antibodies. SIOPs have narrow size distribution and high magnetic susceptibility, and ACE has excellent chemiluminescent properties such as low background signal and no need for a catalyst. The researchers demonstrated that ExoNANO allows the quantitative analysis of exosomes in the range of 2.92 ×105 to 2.80×108 particles/μL, with a limit of detection of 2.63×105 particles/μL. Using ExoNANO, they quantified exosomes in cell culture medium and clinical biofluids such as serum, saliva, ascitic fluid, and cerebrospinal fluid. The researchers believe that ExoNANO might pave the way for the rapid isolation and quantitative analysis of exosomes for routine clinical applications.
ExoNANO – rapid and quantitative analysis of exosomes by a chemiluminescence immunoassay using superparamagnetic iron oxide particles
Wang Y, Liu Z, Wang X, Dai Y, Li X, Gao S, Yu P, Lin Q, Fan Z, Ping Y, Wang D, Lin X, Zheng Z, Liu W, Tao Z. (2019) Rapid and Quantitative Analysis of Exosomes by a Chemiluminescence Immunoassay Using Superparamagnetic Iron Oxide Particles. J Biomed Nanotechnol 15(8):1792-1800. [abstract]