Temcam xf416

The ED patterns of the monoclinic l-histidine crystals were measured using a JEM-F200 transmission electron microscope (JEOL Ltd., Tokyo, Japan) operating at 200 kV. The sample was maintained at the ambient temperature during measurements. The diffraction data were recorded using a high-sensitivity CMOS camera (TemCam XF-416, TVIPS GmbH, Gauting, Germany) with × 4 binning (1024 × 1024 pixels). The camera length (874 mm) was calibrated using a gold polycrystal specimen. In order to minimize the dose damage, electron dose rate was set to a very low level of 0.01 elÅ⁻²s⁻¹. A set of ED patterns was collected under the continuous rotation from −30° to +30° with a rate of 0.25° s⁻¹ using RECORDER software (System In Frontier Inc., Tokyo, Japan). This condition yielded a total irradiation time of 240 s, corresponding to 2.4 elÅ⁻² total dose. Exposure time was set to 4 s, giving 60 images in total. The granular particles of monoclinic l-histidine crystals were grounded by glass plate and distributed on a TEM grid supported by ultra-thin carbon film. The collected ED patterns were indexed and converted into the SHELX format using XDS [44 (link)]. Initial structure was solved by SIR2019 using direct method [45 (link)]. The solutions were refined after correcting atomic assignments and adding protons by SHELXL program with ShelXle interface [46 (link),47 (link)].

For negative stain electron microscopy, a 10 µL sample corresponding to the 80S ribosome peak (fraction 5) was applied directly after fractionation to a glow discharged 400-mesh grid (EMS, CF400-Cu-50) and incubated for 5 min at room temperature. The grid was stained with 2% uranyl acetate twice for 1 min each. Excess fluid was blotted away with Whatman filter paper after each incubation period (Cytiva, 1001-090). Images were collected on an FEI F20 electron microscope operated at 120 kV and equipped with a TVIPS TemCam XF416 camera. Images were taken at a magnification of 62,000×, and a pixel size of 0.17 nm.

A 3.4 μL sample of purified VLP solution between 0.02–0.05 mg ml^–1 was applied to a carbon coated copper/Formvar grid and negatively stained with 2% w/v uranyl acetate, pH 4. Images were taken by a TEMCAM XF416 (TVIPS, Oslo, Norway) camera in a CM200 (Philips, Amsterdam, Netherlands) electron microscope at an acceleration voltage of 200 kV. ImageJ software (version 1.51) (Maryland, United States) was used to process the TEM images and add scale bars.

The stock sample was diluted with water (1:99), placed on a carbon-coated copper grid and left to air dry for two hours. The grid with the sample was then placed in a JEM-2100F Field Emission Electron Microscope and imaged at 200 kV to acquire Transmission Electron Microscope (TEM) images. Images were collected using a TemCam-XF416 Complementary metal–oxide–semiconductor (CMOS) camera (Tvips, Germany).

The surface microstructure of the Nb-Ti thin-film alloys along the library was characterised with a field emission scanning electron microscope (FE-SEM, Zeiss Leo 1550 VP, Jena, Germany). Images were acquired at a 3 kV acceleration voltage using the in-lens detector. With these experimental conditions, the surface grains of the Nb-Ti alloys could be best observed.
To shed light on the structure and chemistry of the specimens at the nanoscale, cross-sectional transmission electron microscopy (TEM) was applied. Characterisation was performed using a JEOL JEM-2200FS electron microscope (JEOL, Tokyo, Japan) operated at 200 kV. The TEM was fitted with an in-column Omega filter and a CMOS-based camera, TemCam-XF416 (TVIPS, Gauting, Germany). Images were captured utilising zero-loss filtering. Cross-sectional lamellae were prepared via focused ion beam (FIB) milling (CrossBeam 1540 XB, Zeiss, Germany). Before cutting, the samples were covered with an electron beam-stimulated Pt deposit, followed by an ion-stimulated Pt sacrificial layer to protect the surface. For qualitative elemental analysis, energy-dispersive X-ray spectroscopy (EDX) was performed in scanning (S)TEM mode utilising an X-Max^N 80 T detector from Oxford Instruments (UK). The data were processed with dedicated Aztec Version 4.0 software.

For electron tomography, semi-thin sections of 250 nm thickness were cut transversally to the root using a Leica Ultracut (Leica Mikrosysteme GmbH, Vienna, Austria) and then, picked up on 75 square mesh copper grids (EMS, Hatfield, PA, US). Sections were post-stained on both sides with uranyl acetate (Sigma, St Louis, MO, US) 2% in H₂O for 10 min and rinsed several times with H₂O. Protein A Gold 10 nm beads (Aurion, Wageningen, The Netherlands) were applied as fiducials on both sides of the sections and the grids were placed on a dual axis tomography holder (Model 2040, Fischione Instruments). The area of interest was taken with a transmission electron microscope JEOL JEM-2100Plus (JEOL Ltd., Akishima, Tokyo, Japan) at an acceleration voltage of 200 kV with a TVIPS TemCamXF416 digital camera (TVIPS GmbH, Gauting, Germany) using the SerialEM software package^{52 (link)}. Micrographs were taken as single or dual-axis tilt series over a range of −60° to +60° using SerialEM at tilt angle increment of 1°. Tomogram reconstruction was done with IMOD software^{50 (link)}, segmentation with Ilastik software package^{53 (link)} and model visualization with Imaris software package (Oxford Instruments).