Tecnai f20 twin microscope

Cryogenic transmission electron microscopy (Cryo-TEM) micrographs were obtained using a Tecnai F20 TWIN microscope (FEI Company, Hillsboro, Oregon, USA) equipped with field emission gun, operating at an accelerating voltage of 200 kV. Images were recorded on the Eagle 4 k HS camera (FEI Company, USA) and processed with TIA software (FEI Company, Hillsboro, Oregon, USA). Specimen preparation was done by vitrification of the aqueous (HPLC-grade water) solutions on grids with holey carbon film (Quantifoil R 2/2; Quantifoil Micro Tools GmbH, Germany). Prior to use, the grids were activated for 15 s in oxygen plasma using a Femto plasma cleaner (Diener Electronic, Germany). Cryo-samples were prepared by applying a droplet (3 μL) of the solution to the grid, blotting with filter paper and immediately freezing it in liquid ethane using a fully automated blotting device, Vitrobot Mark IV (FEI Company, Hillsboro, Oregon, USA). After preparation, the vitrified specimens were kept in liquid nitrogen until they were inserted into a cryo-TEM-holder Gatan 626 (Gatan Inc., Pleasanton, California, USA) and analyzed in the TEM at −178 °C. Pictures were processed using ImageJ software.

Cryogenic Transmission Electron Microscopy images were obtained using a Tecnai F20 TWIN microscope (FEI Company, Hillsboro, OR, USA) equipped with a field emission gun, operating at an acceleration voltage of 200 kV. Images were recorded on an Eagle 4k HS camera (FEI Company, Hillsboro, OR, USA) and processed with TIA software (FEI Company, Hillsboro, OR, USA). Specimen preparation was done by vitrification of the aqueous solutions on grids with holey carbon film (Quantifoil R 2/2; Quantifoil Micro Tools GmbH, Jena, Germany). Before use, the grids were activated for 15 s in oxygen plasma using a Femto plasma cleaner (Diener Electronic, Ebhausen, Germany). Cryo samples were prepared by applying a droplet (3 µL) of the solution to the grid, blotting with filter paper, and rapid freezing in liquid ethane using a fully automated blotting device Vitrobot Mark IV (FEI Company, Hillsboro, OR, USA). After preparation, the vitrified specimens were kept under liquid nitrogen until they were inserted into a cryo-TEM holder Gatan 626 (Gatan Inc., Pleasanton, CA USA) and analyzed in the TEM at −178 °C. The Cryo-TEM measurements were performed under a contractual service agreement with CMPW PAN in Zabrze, Poland.