Fig. 7

Scanning Electron Micrograph (SEM) of TNT-like structures penetrating the 400 nm pores of the transwell membrane. MSTO cells were grown on the transwell membrane culture inserts for 48 h and then fixed using PFA. On the bottom of the membrane, TNT-like structures were identified and imaged without staining. The image provides evidence that TNTs have the capacity to penetrate and traverse the transwell membrane via the 400 nm-sized pores of the polyester filter (scale bar 1000 nm). that formed through the membrane pores, and extended beyond the membrane are shown, marked by arrowheads. Several TNTs were disrupted by the fixation process, but are shown in cross-section (arrows)