We have improved the sample preparation process by providing a hydrophilic coating through a hydrophilic treated copper mesh. With this treatment, the samples are more easily and uniformly adsorbed on the carbon film. We took transmission electron microscopy (TEM) images of exosomes and liposomes. The exosomes showed a typical cup-like morphology (Figure 2A) and the spherical liposomes were uniformly distributed (Figure S2).