Jem 2011 transmission electron microscope

Assay of Aβ_1-42 oligomers formation using Transmission electron microscopy (TEM) images was performed as previously described5 (link). Briefly, synthetic Aβ_1-42 was dissolved in HFIP to 1 mg/ml, evaporated under vacuum, and reconstituted in DMSO to 5 mM. Then Aβ_1-42 was diluted to 20 μM by using 10 mM sodium phosphate (pH = 7.4), and incubated with 1 μM bis(heptyl)-cognitin. The TEM samples were prepared by placing 2 μl of the pre-incubated solution on a carbon-coated grid. The samples were stained with 1% uranylacetate and then placed on a clean paper for removing excess staining solution. The grids were thoroughly examined using JEM-2011transmission electron microscope (JEOL, Tokyo, Japan).

The transmission electron microscopy (TEM) was adopted for the morphology and element analysis on a JEOL JEM-2011 transmission electron microscope with an energy-dispersive X-ray spectroscopy (EDS) detector operated with an accelerating voltage of 200 kV. The scanning electron microscope (SEM) images and EDS mapping images were determined by a Hitachi S4800 scanning electron microscope with a working voltage of 3 kV. The low-angle X-ray diffraction (XRD) patterns were recorded on a D/max2550VB3+/PC X-ray diffractometer with Cu Kα radiation (λ = 0.15418 nm). The Fourier transform infrared (FT-IR) spectra were obtained on a Nicolet 6700 FT-IR spectrometric analyzer using KBr discs in the region of 4000-500 cm^-1. Zeta potential and dynamic light scattering (DLS) particle size distributions were obtained using a Malvern Zetasizer Nano-ZS90 with the samples dispersed into ethanol. The nitrogen (N₂) adsorption-desorption isothermal curve and the corresponding pore-size distribution measured by the Micromeritics Tristar 3000 system were used to detect porous structures at 77 K. The surface area (S_BET) and pore volume (V_pore) were determined by Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) analysis, respectively. The pore-size distribution curves were obtained by BJH analysis.

Grids prepared
for TEM visualization were used for EDX spectroscopy analysis. The
EDX spectrum for each sample was acquired in a JEM-2011 transmission
electron microscope (JEOL Ltd., Japan) operating at 200 kV, equipped
with an EDS X-max detector (Oxford Instruments, UK). Spectra were
analyzed using INCA Software (ETAS group, Germany) and represented
with GraphPad Prism 5.0 (GraphPad Software, USA).

The morphology of the distinct types of produced DELOS nanovesicles was assessed by cryogenic transmission electron microscopy using a JEOL JEM-2011 transmission electron microscope (JEOL Ltd., Tokyo, Japan) operating at 200 kV. In the case of the DELOS nanovesicle dispersions, a small drop of the sample was directly placed on a copper grid coated with a perforated polymer film. Conversely, in the case of DELOS nanovesicles-based hydrogels, they were diluted 1:100 in water for an adequate fixation and preservation of the hydrogel sample in the grid. Afterward, the excess of the sample was removed by blotting with filter paper. Immediately after film preparation, the grid was plunged into liquid ethane held at a temperature just above its freezing point (−179.15 °C). The vitrified sample was then transferred to the microscope for analysis. To prevent sample perturbation and the formation of ice crystals, the specimens were kept cold (−196.15 °C) during both the transfer and viewing procedures. Images were recorded on a Gatan 724 CCD camera under low-dose conditions using Digital Micrograph 3.9.2. (Gatan Inc., Pleasanton, CA, USA).

Transmission electron microscopy (TEM) morphologies of Poly(St-MMA-AA) nanoparticles were detected by JEOL JEM-2011 Transmission Electron Microscope. Prior to conducting TEM measurement, Poly(St-MMA-AA) nanoparticles were first pre-dispersed and diluted in aqueous solution to approximately 100 ppm, 10 μL nanoparticle solution were then deposited on 400-mesh carbon-coated copper (Cu) grids, and the sample was completely air-dried prior to TEM observation.