Etx produces the death of 1G11 mouse endothelial cells. MDCK cells (A–F) and 1G11 cells (G–L) were treated with pEtx (A–C and G–I) or Etx (D–F and J–L) for 120 min at 37 °C. Prior to pEtx or Etx treatment, the cells were incubated with propidium iodide (PI). Pictures correspond to 40 min of pEtx or Etx action in MDCK cells, and 90 min in 1G11 cells. Differential interference contrast (DIC) pictures were taken to see the change in cell morphology (A, D, G and J). Note a rounded morphology after Etx exposure compared to the elongated morphology in pEtx treatment in both MDCK and 1G11, and PI staining was also detected (red, E and K, respectively). Bar 25 µm.