Fastscan dimension icon

Microscopy glass slides were treated with 100 µg/ml solution of purified active and inactive polysaccharides for 10 min and rinsed with ultrapure water. AFM measurements were performed in ultrapure water, using a Fastscan Dimension Icon with Nanoscope V controller (Bruker). Images were obtained in Peak Force tapping mode, using gold-coated silicon nitride tips (NPG, Bruker), with a maximum applied force of 500 pN, a scan rate of 1 Hz, a peak force amplitude of 300 nm, and a peak force frequency of 2 kHz. For quantifying coated-surface hydrophobicity by means of chemical force microscopy, hydrophobic tips were prepared by immersing gold-coated silicon nitride tips (NPG, Bruker) for 12 h in 1 mM solution of dodecanethiol (Sigma) in ethanol, rinsed with ethanol and dried with N₂. Spatial mappings were obtained by recording 32 × 32 approach-retract force-distance curves on 5 µm × 5 µm areas, with a maximum applied force of 500 pN, and an approach and retraction speed of 500 nm/s.

Performed in deionized water using a Fastscan Dimension Icon (Bruker Corporation, Santa Barbara, CA). Images were recorded in peak force tapping mode using oxide sharpened micro-fabricated Si₃N₄ coated with Au cantilevers with a nominal spring constant of ~0.24 N/m (Bruker Corporation). Conidia were harvested from 12–15 days old malt agar slants maintained at ambient temperature, washed extensively with Tween-water, followed by washing twice with MilliQ water, subjected to PFA-fixation (Aimanianda et al., 2009 (link)) and then immobilized by mechanical trapping into porous polycarbonate membranes (Millipore). After filtering a concentrated conidial suspension, the filter was gently rinsed with deionized water, carefully cut, attached to a steel sample puck using a small piece of double face adhesive tape, and the mounted sample was transferred into the AFM liquid cell while avoiding dewetting. Data processing was performed using the commercial Nanoscope Analysis software (Bruker Corporation). At least eight conidia were analyzed to determine the percentage of conidia completely and partially covered by the surface rodlet-layer.