Supra 55 vp feg scanning electron microscope

Samples of B. vulgaris leaf fragments with Pg aecia were first mounted on aluminum stubs using Tissue Tek^R (BDH Laboratory Supplies, UK). The stubs were then immediately plunged into liquid nitrogen slush at approximately −210 °C to cryopreserve the material. Samples were transferred onto the cryostage of an ALTO 2500 cryotransfer system (Gatan, UK) attached to a Zeiss Supra 55 VP FEG scanning electron microscope (Zeiss SMT, Germany) or the same type of cryo-system on a FEI Nova NanoSEM 450 (FEI, The Netherlands). Sublimation of surface frost was performed at −95 °C for ~3 min before the samples were sputter coated with platinum for 2 min at 10 mA, at colder than − 110 °C. After sputter-coating, the samples were moved onto the cryostage in the main chamber of the microscope, held at −125 °C. The samples were imaged at 3 kV and digital TIFF files stored. Images were analyzed using ImageJ.

Samples were fixed in FAA (50% ethanol, 5% acetic acid, 3.7% formaldehyde) for 24 h, washed in 50% ethanol, dehydrated in an ethanol series (50%, 70%, 80%, 90%, four times in 100% ethanol for 30 min each at room temperature), and critical point dried using a Leica EM CPD300. Gynoecia were dissected from dried samples and mounted on stubs for coating in gold using an Agar Scientific high-resolution sputter coater and imaged using a Zeiss Supra 55VP FEG scanning electron microscope.

Samples were mounted on aluminium stubs using Tissue Tek^R (BDH Laboratory Supplies, Poole, England). The stubs were then immediately plunged into liquid nitrogen slush at approximately − 210 °C to cryopreserved the material. The samples were transferred onto the cryostage of an ALTO 2500 cryotransfer system (Gatan, Oxford, England) attached to a Zeiss Supra 55 VP FEG scanning electron microscope (Zeiss SMT, Germany) or the same type of cryo-system on an FEI Nova NanoSEM 450 (FEI, Eindhoven, The Netherlands). Sublimation of surface frost was performed at − 95 °C for ~ 3 min before the samples were sputter coated with platinum for 2 min at 10 mA, at colder than − 110 °C. After sputter-coating, the samples were moved onto the cryo-stage in the main chamber of the microscope, held at − 125 °C. The samples were imaged at 3 kV and digital TIFF files were stored.

Scanning electron microscopy (SEM) was performed on a Zeiss Supra 55 VP FEG Scanning Electron Microscope (Zurich, Switzerland). Micrographs were taken at a 3.5-mm working distance and under a 5-keV beam voltage (aperture 20 mm). The samples were carbon-coated with a 1–2-nm-thick layer.
SAXS experiments were performed on the SAXS/WAXS beamline at the Australian Synchrotron under the grant M5826 in March 2013. The samples were mounted within a specially designed stainless steel gas tight module with two parallel quartz windows reinforced with Kapton tape, as presented in Figure A2, and fitted onto the previously described single gas permeation rig. The high brilliance and coherence of the beam allowed for a very short acquisition time (300 ms). The energy of the beam was set at 11 keV, and scattering from the Kapton tape was determined independently and removed as background from the signals. The camera length of this series of test was 0.6 m, and the wavelength of the collimated beam was 1.0332 Å beam energy of 9.8 keV. The size of the X-ray beam was 150 μm × 250 μm. The small scattering angle, q, was inversely proportional to the scatterer diameter at small scattering angles as per Equation (1):

where d is the space dimension of the scatterers (nm), and q is the absolute value of the scattering vector (Å⁻¹).

Streptomyces samples were mounted on an aluminium stub using Tissue Tek^R (BDH Laboratory Supplies, Poole, England) and plunged into liquid nitrogen slush. The sample was transferred onto the cryo-stage of an ALTO 2500 cryo-transfer system (Gatan, Oxford, England) attached to either a Zeiss Supra 55 VP FEG scanning electron microscope (Zeiss SMT, Germany) or an FEI Nova NanoSEM 450 (FEI, Eindhoven, The Netherlands). Sublimation of surface frost was performed at −95 °C for 3 min before sputter coating with platinum for 150 s at 10 mA. The sample was moved onto the main cryo-stage in the microscope for imaging at 3 kV and digital TIFF files were stored. All uncropped SEM images, including additional images of the same strain, are shown in Supplementary Figs. 11–15.