Fig. 2

cfDNA fragmentation is a two-step process involving successive intracellular and extracellular digestion. A DNA size distribution profiles revealed by sWGS in pellets from HL60 cells exposed to RT for 24 h, 36 h, and 48 h. Bottom panels are enlarged views of the boxed areas in the top panels. B DNA size distribution profile in the supernatant of HL60 cells, which were exposed to RT for 24 h. C DNA size distribution profiles in the lysate of HL60 cells, which were exposed to RT for 24 h to induce apoptosis in advance, then treated with DNASE1. D Model of the stepwise cfDNA fragmentation process