Tecnai g2 20 twin tem

Transmission electron microscopy (TEM) analysis was performed according to previous results (Qin et al., 2019 (link)). Sf9 cells infected with vAc-ph, vAc^ac75F54S-ph, or vAc^ac75REP-ph at an MOI of 5 were fixed with 2.5% (v/v) glutaraldehyde for 2 h and harvested at 24, 36, and 48 h post infection (p.i.). Ultrathin sections were visualized by a FEI Tecnai G² 20 TWIN TEM. For immunoelectron microscopy analysis, Sf9 cells were infected with vAc-ph, vAc^ac75F54S-ph or vAc^ac75REP-ph at an MOI of 5. At 48 h p.i., the cells were fixed with 1% paraformaldehyde-0.5% glutaraldehyde for 10 min at 4°C, refixed with 2% paraformaldehyde-2.5% glutaraldehyde for 1 h at 4°C and then dehydrated and embedded according to previous methods (Xu et al., 2019 (link)). Ultrathin sections were immunostained with anti-AC75 pAb (1:50) as the primary antibody. Goat anti-rabbit IgG coated with gold particles (10 nm; Sigma, Darmstadt, Germany) was used as the secondary antibody (1:50). Ultrathin sections were also visualized by using the FEI Tecnai G² 20 TWIN TEM.

For electron microscopy analysis, samples were adsorbed onto hexagonal, carbon–coated copper grids for 30–40 s, which were then washed by floating on water droplets. Excess fluid was removed with filter paper and the grids were negatively stained with 2% (w/v) uranyl acetate (UA) for 20 s. Particles were imaged using a FEI Tecnai G2 20 Twin TEM.

TEM was utilized to study the microstructures of S. suis following vraSR deletion [58 (link)]. WT SC19, mutant ΔvraSR and complementary strain CΔvraSR cells harvested at mid-log growth phase were fixed with 2.5% glutaraldehyde overnight at 4°C, postfixed with 1% osmium tetroxide for 2h, dehydrated in ethanol and embedded in epoxy resin, after which the cell morphologies were examined on a model Tecnai G² 20 TWIN TEM (FEI Company) at 200 kV. High-magnification images were captured with a digital camera system.