Bm ceta camera

Cryo-TEM was performed using a Talos F200C CryoTwin Transmission Electron Microscope (Thermo Fisher Scientific, Waltham, MA, USA) operated at an acceleration voltage 200 kV in TEM uP SA Zoom Image mode. Images were recorded on the BM-Ceta camera (Thermo Fisher Scientific).
First, the grids with holey carbon film (Quantifoil R 1.2/1.3; Quantifoil Micro Tools GmbH, Großlöbichau, Germany) were activated for 20 s at 8 mA using a Femto plasma cleaner (Diener Electronic, Ebhausen, Germany). Sample preparations were performed by applying 5 μL of the solution on the grid. Excess liquid was removed with filter paper and the samples were vitrified immediately after blotting by plunging the grid into liquid ethane held at approximately −183°C. Samples were kept under liquid nitrogen until TEM analysis. Images at 45,000× were captured for each sample.

Four microliters of 2 mg/mL polymersome dispersions were dropped onto glow discharged carbon-coated lacey copper grids (300 mesh; Electron Microscopy Science). Samples were blotted in a commercial vitrification system (Vitrobot Mark IV; Thermo Fisher) and after plunge freezing the grids were transferred at −178 °C into a Gatan 626 cryoholder (Gatan) and imaged in a Tecnai F20 microscope (Thermo Fisher) operated at 200 kV. Resulting cryo-EM images were recorded with a BM-Ceta camera (4,096 × 4,096 pixels; Thermo Fisher).