Fig. 1: A panel of human cell lines reveals convergent cfDNA release kinetics and divergent fragmentation patterns.

a Release of cfDNA in vitro over time. Data represent mean fold change ± SEM in absolute DNA release from Day 1 for each cell line, with n = 3 biologically independent samples. b Electropherograms of samples from a, assessing changes in cfDNA release with increased cell incubation periods, were individually run at least n = 3 times and representative traces are shown. c Degradation of in vitro cfDNA over time at physiologic temperatures. Data represent mean fold change ± SEM in absolute DNA quantity from Day 0 for each cell line, with n = 3 biologically independent samples. d Electropherograms of samples from c, assessing the degradation of cfDNA in culture media after removal from cells, were individually run at least n = 3 times and representative traces are shown. e Quantification of cfDNA release from cell lines in culture. Data represent mean fold change ± SEM in DNA release normalized to cell concentration at time of collection for each cell line, with n = 3 biologically independent samples. f Fragmentation patterns of selected cell lines from the cfDNA panel. Cell lines A549, MCF-7, and Sum185-PE (purple text) are representative of cell lines with a left skew, CAL51, HepG2/C3A, and ZR-75-1 (yellow text) are representative of cell lines with a right skew. Representative traces shown of at least n = 3 runs.