Tecnai g2 biotwin transmission electron microscope

Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) was performed at the Manawatu Microscopy and Imaging Centre, Massey University, Palmerston North, New Zealand. SEM was performed on an aliquot of sample 3 (see section on Quinella-enriched samples, above) fixed to a Formvar grid (Sigma-Aldrich, St. Louis, MO, USA), stained with 2% (w/v) uranyl acetate and examined with a FEI Quanta 200 scanning electron microscope (Philips Electron Optics, Eindhoven, The Netherlands). Part of sample 3 was prepared for TEM by washing the cell pellet three times in sterile water, resuspending in modified Karnovsky’s fixative (2% [w/v] paraformaldehyde and 3% [w/v] glutaraldehyde in 0.1 M sodium phosphate buffer, pH 7.2) for embedding in resin (Procure 812; ProSciTech, Qld, Australia), and thin sections made using an EM UC7 ultra-microtome (Leica Microsystems, Wetzlar, Germany). TEM used a Tecnai G2 Biotwin transmission electron microscope (FEI, Hillsboro, OR, USA). Electron microscopy used XT Microscope Control and TUI version 4.5 software (FEI).