Figure 3. High stress in the peripheral ring prepares the cell for popping.

(A) Von Mises stress distribution in the “ready-to-pop” S. aureus cell wall (state 3 in Fig. S6) modeled as a linear elastic material (see Supplementary Materials for details of model construction). Color represents the relative magnitude of stress. The stress at the peripheral ring (red arrow), where the cell wall splits open during popping, is higher than elsewhere in the outer wall. (B) Enlarged views of a cut-through slice of the cell in (A) shows high von Mises stress at the peripheral ring (red arrow) as well as the stress distribution in the circumferential and axial directions respectively.