Fig. 4.

Exosome characterization methods; (i) Biophysical characterization: DLS [97], NTA [98], and flow cytometry [99]; (ii) Imaging: SEM [97], TEM [100], and AFM height imaging [98]; (iii) Protein characterization: ELISA [101], western blotting [100], and proteome profiling [102]; and (iv) Nucleic acid characterization: RNA-Seq and microarray gene expression platforms, genes (columns) and samples (rows) are organized hierarchically with dendrograms and clusters, upregulation is indicated by red on the heatmap, whereas downregulation is indicated by blue [103].