Sigma vp electron microscope

Scanning electron microscopy (SEM) was performed to analyze the architecture of PAO1, PAO1mucA22, and SH1000 cells treated with NAC and CYST. The cells were drop-casted on titanium coupons by depositing 5 μL of cell suspension to characterize the effects of disrupting agents on planktonic cells. To assess biofilm architecture, the colonies of the respective strains of bacteria were grown on LB agar plates and collected on titanium coupons using capillary peeling techniques (Yan et al., 2018 (link)). The samples were then fixed in 2.5% glutaraldehyde for 12 h at room temperature. Thereafter, samples were washed thrice in 154 mM NaCl solution, followed by a series of dehydrations in 30%, 50%, 70%, 90%, and 100% ethanol for 10 minutes each. To achieve complete drying while preserving cell morphology, the samples were dehydrated thrice in 100% ethanol prior to critical point drying with 100% ethanol and liquid CO₂ in a Leica Balzer CPD030 (Leica, IL). Imaging was done with the Zeiss SIGMA VP electron microscope at an accelerating voltage of 5 kV.

Silk films on glass slides were attached to an aluminum stub using
carbon tape and then sputter-coated with 5 nm of gold/palladium. Images
were taken with a Sigma VP electron microscope (Zeiss) using an acceleration
voltage of 1.5 kV and a SE2 or an in-lens detector.