Figure 4

Characterization of the critical mechanical impact for cell injury using Hs27 cells using an average confluency metric (a–c) versus a local area confluency metric (d–f), monitored over 160 h. The average confluency curves (a) 5 cm-, 10 cm-, 15 cm-, and 20 cm-single-drops, (b) 15 cm-/20 cm-single-drops as well as 10 cm-, 15 cm-, and 20 cm-five-drops, (c) 30 cm- and 40 cm-single-drops on the cell cultures. Passage 6, 8, and 11 were used for (a), (b), and (c), respectively. The acceleration measured during 30 cm- and 40 cm-drops are shown in the inset of (c). The local confluency curves for Control 2, 30 cm-drop, and 40 cm-drop from (c) are shown in (d–f), respectively. (g-i) and (-ii) are live cell images corresponsding to area C3 in (f) before and after the impact, respectivly (also see the Supplementary Movie 2). (h) and (i) are high speed camera images of the cell culture setup during 40 cm-drop. Cavitation bubbles are observed on the petri dish (see the arrows in (i)).