Fig. 2

Characterization of exosomes and Apt-TDNA. a Characterization of size and number of exosomes using nanoparticle tracking analysis. b The widespread distribution of CD63 protein on the membrane of A549-derived exosomes was characterized by flow cytometry. c Purified bare exosomes (left) and PDA coated exosomes (right) observed using TEM. d Four Apt-TDNA monomers before (1–4) and after (5–8) TCEP pretreatment were characterized by 12.5% PAGE. e Characterization of Apt-TDNA by AFM. f In 2.5% agarose, the migration rates of thiolated monomers, assembly intermediate and Apt-TDNA are from fast to slow