Recent Technical Developments in the Standardized Separation and Measurement of Extracellular Vesicles
Poster Oct 20, 2014
Amy Phillips (1), Robert Vogel(2), and Murray F. Broom(1)
There is an urgent need for a standardized, effective and practical separation method for exosomes and other extracellular vesicles (EVs). The use of SEC columns for EV separation has been proposed by Boing et al. and a large number of standardized columns are now being tested in a worldwide program.
Most EV measurement systems are not easily standardized and do not provide the actual number of particles. In particular NTA provides substantially different number values depending on the illumination settings and liquid characteristics.
The use of a single number for particle concentration is fundamentally flawed because the number given will naturally vary with the size range being measured. The size range to which the concentration number applies needs to be specified. For instance C70-200 would be the number of particles from 70nm to 200nm in size. TRPS measurement with routine use of calibration particles is able to provide verifiable data that represents the actual number of particles and sizes with sufficient accuracy to be directly comparable among different research groups.
Furthermore recent development in the aptamer field and particle by particle surface charge measurement have enabled the use of aptamers to detect and measure proteins on the surfaces of EVs. We present recent work in detecting and measuring Annexin on the surface of exosomes.
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