TEM Imaging of Microbial Cells

Cells were prepared and pre-grown as previously described. The culture was grown in the presence of 1 mM IPTG for 6 h and harvested by centrifugation. Samples were prepared as previously described (Andersen et al. 2021 (link)). Semi-thin sections (2 μm) were cut using a glass knife and ultramicrotome (Leica Ultracut, Leica Microsystems, Wetzlar, Germany) and stained with 1% toluidine blue (Millipore) and 1% Borax (LabChem). Ultra-thin sections (50–70 nm) were cut using a diamond knife (Jumdi, 2 mm) and the ultramicrotome, contrasted in 2% uranyl acetate (Polyscience) and lead citrate (Merck). The samples were examined in a Philips CM100 transmission electron microscope, and images were obtained using an Olympus Morada camera and iTEM software (Olympus).