Fig. 1

Characterization of BALF and plasma EV DNA. a. Size distribution of BALF EV. BALF was ultracentrifuged to obtain pallets and remove cells and debris, which was resuspended in 200 μl PBS. Sizes of purified EVs were determined using Zetasizer Nano ZS. Average size distribution from six separate experiments is plotted in percentage distribution according to their size. All six distributions are shown in Additional file 1: Figure S1. b. Size distribution of plasma EV. Plasma was ultracentrifuged to obtain pallets and remove cells and debris, which was resuspended in 200 μl PBS. Sizes of purified EVs were determined using Zetasizer Nano ZS. Average size distribution from three separate experiments is plotted in percentage distribution according to their size. All three distributions are shown in Additional file 1: Figure S2. c. EM image of BALF EVs. Samples for EM analysis were negatively stained. The size bar in the EM image indicates 100 nm. d. EM image of plssma EVs. Samples for EM analysis were negatively stained. Plasma EVs indicated by red arrows. The size bar in the EM image indicates 100 nm. e. Detection of dsDNA in BALF EVs by performing immuno-EM. DsDNA was labeled with a mouse monoclonal antibody and colloidal gold-conjugated secondary antibodies. The solid black dots indicate DNA (indicated by red arrows). f. Gel-like images show the size and amount of EV DNA and cfDNA determined using the bioanalyzer. First lane shows the standard size ladder distribution, and numbers on the left indicate corresponding sizes. The second and third lanes show the size and amount of EV DNA and cfDNA, respectively. g. Amplification curve obtained by performing real-time PCR. Exon 19 deletion in EGFR was determined by performing peptide nucleic acid (PNA)-mediated PCR clamping. Both EV DNA and cfDNA were extracted from 1 ml BALF, and 70 ng EV DNA and cfDNA were used for performing PCR