Fei quanta 600 fe sem

Drain belt sections (n = 6; 4 middle, 2 edge) were prepared for scanning electron microscopy to visualize and identify the location of any attached bacteria or biofilms that survived sanitation. Belt sections were snapped and broken inside the collection bags into approximately 1-to 3-cm 2 pieces. Belt pieces with visible crevices or including areas that were more difficult to access during sanitation were selected for analysis. Belt pieces were placed in scanning electron microscopy fixa-tive (1% paraformaldehyde and 2.5% glutaraldehyde in 0.1 M sodium cacodylate) overnight and submitted to the Oregon State University Core Microscopy Facility (Corvallis) for dehydration with ethanol and critical point dryer (EMS 850, Electron Microscopy Sciences). Prepared belt pieces were mounted and sputter coated with 60% gold, 40% palladium (Cressington 108A, Ted Pella) and imaged using an FEI Quanta 600F eSEM (Thermo Fisher). Two instrument settings were used for imaging: 5.00 kV with a 5.1-mm working distance or 10.00 kV with an 8.9-mm working distance.