Em 906 microscope

The morphology of CUB19 was detected by transmission electron microscopy (TEM) using a Zeiss EM 906 microscope (Carl Zeiss Microscopy Deutschland GmbH, Oberkochen, Germany) and negative staining as in a previous study [14 (link)]. Shortly, 15 µL of phage solution was dropped onto Parafilm and transferred onto a carbon-coated and glow discharged (Leica MED 020, Leica Microsystems, Wetzlar, Germany) Ni-mesh grid (G2430N; Plano GmbH, Wetzlar, Germany), and left to adsorb for 10–15 min at room temperature. After washing the grids three times with Aquadest, they were treated with 1% aqueous uranyl acetate (SERVA Electrophoresis GmbH, Heidelberg, Germany) for 20 s for negative staining. Grids were air dried and then imaged by TEM at a voltage of 80 kV. Phage size was measured using the image processing program ImageJ.JS 1.53 m [15 ].

The virion morphology characteristics were visualized by transmission electron microscopy (TEM) using the negative staining technique. A volume of 15 µL of phage solution was dropped onto parafilm prior transferal onto a Ni-mesh grid (G2430N; Plano GmbH, Wetzlar, Germany) that has previously been carbon-coated and glow discharged (Leica MED 020, Leica Microsystems, Wetzlar, Germany). The grid is then let to adsorb for 10–15 min at room temperature and then washed three times with Aquadest and treated with 1% aqueous uranyl acetate (SERVA Electrophoresis GmbH, Heidelberg, Germany) for 20 s for negative staining. Afterwards, excess staining was removed with filter paper. Grids were air dried and then imaged by TEM using a Zeiss EM 906 microscope (Carl Zeiss Microscopy Deutschland, Oberkochen, Germany) at a voltage of 80 kV. The image processing program ImageJ [27 ] was used for phage size measurements.

The morphology of CUB-EPI_14 was detected by transmission electron microscopy (TEM) using negative staining. Ten randomly selected viral particles were evaluated for size calculation. An aliquot of 15 µL of the high-titer phage particle preparation was dropped onto parafilm before the transferal onto a Ni-mesh grid (G2430N; Plano GmbH, Wetzlar, Germany), which has been carbon-coated and glow discharged (Leica MED 020, Leica Microsystems, Wetzlar, Germany), and allowed to adsorb for 10–15 min at room temperature. The grids were washed three times with Aquadest and subsequently treated with 1% aqueous uranyl acetate (SERVA Electrophoresis GmbH, Heidelberg, Germany) for 20 s for negative staining, followed by the removal of excess staining with filter paper. Grids were air-dried and then imaged by TEM using a Zeiss EM 906 microscope (Carl Zeiss Microscopy Deutschland; Oberkochen, Germany) at a voltage of 80 kV. Phage size measurements were calculated using the image processing software ImageJ.JS 1.53 m (https://imagej.nih.gov/ij/, accessed on 2 May 2022) [16 (link)].