CLSM images of Test Model I.

(A) Cy5 channel (blue) to visualize the polymer surface. (B) AF488 channel (green) to distinguish spores from background signals (potential polymer autofluorescence and debris). (C) PMA channel (red) to detect disintegrated spores. (D) overlay of all channels. (E) shows enlarged detail of Fig. 2D. (F) CTC channel (yellow) show spores with metabolic activity in the presence of provided nutrients (different position on Test Model I is shown). (G) z-axe projection from 90° calculated from z-stacks scanned with a 50% overlap of each 0.4 µm section (blue horizontal line indicates the surface of the adhesive). (H) abstracted scheme of Test Model I interpreted from Fig. 2G – intact spores colored in green, disintegrated spores are red-orange, blue glowing line demonstrates polymer surface, gray area represents polymer material. Spores of B. safensis, were stained with AF488 prior to embedding (Fig. 2B), but with PMA after embedding (Fig. 2C). The PMA signals were visible in a layer of about 3 µm, whereas the AF488 signal was detectable to a depth of 10 µm (spores were introduced into deeper layers during embedding; PMA could penetrate the polymer to stain spores up to a depth of 3 µm). All images, overlays and projections were achieved with the Zeiss LSM Image Browser Software.