Fig. 3.

Illustrations on the effect of acoustic waves is separation of exosomes from other blood components. (A) Separation of synthetic microparticles and submicrometer particles using the acoustofluidic cell-removal module. Polystyrene particles with diameters of 5.84 ​μm (not labeled) and 970 ​nm (labeled with Dragon Green fluorescent dye) were processed through the acoustic field. The taSSAW field deflected microparticles to the waste outlets. The acoustic radiation force was not sufficiently large to move the submicrometer particles, which were therefore separated from microparticles at the outlet. White stripe in the two left panels indicates the centerline location of the CCD (charge-coupled device) image sensor. (Scale bar: 500 ​μm). (B) Isolation of exosomes from whole blood using the integrated device using acoustofluidics. In the experiments, inlet A is for whole blood; inlets B, C, and E are for sheath flows. Outlet D is cell waste. Outlets F and G are for isolated exosomes and vesicle waste, respectively. Images were taken under the microscope at the corresponding areas of the device. Blood components were directed to each corresponding outlet when the acoustic wave was on. White stripe in the four grayscale panels indicates the centerline location of the CCD image sensor. (Scale bar: 500 ​μm). (C)TEM images of isolated exosomes. The exosomes (red arrows) have a characteristic round shape and a cup-like structure. The image was reproduced from the article published in The Proceedings of the National Academy of Sciences (PNAS) by Mengxi Wu, Tony J Huang and Co-workers in the year 2017 [412]. Permission was obtained from the publisher. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)