Figure S1.

CryoFIB-Milling of Anabaena Filaments, Related to Figure 1

(A) Shown is a cryo-scanning electron microscopy (SEM) image of an EM grid with plunge-frozen Anabaena filaments.

(B) Shown is one example for the preparation of a lamella through a filament. The target was identified in SEM view (SEM view, pre-milling). The focused ion beam (FIB) was used to inspect the same filament from a shallow angle (FIB view) and to choose a milling pattern (red box, upper panel). Material was then removed using the FIB and inspected again (FIB view, lower panel). The final lamella was inspected again by SEM (SEM view, post-milling).

(C) The procedure was repeated for 9-24 lamellae. Shown is a SEM overview image of a grid area with seven lamellae.

(D) Two examples of cryoFIB-milled lamellae through Anabaena filaments. Details like cell outline (arrowheads) or thylakoid membranes are already detectable.