Mfp 3d afm microscope

For imaging fg monomers and soluble polymers, adsorption to polystyrene (PS) and to trioctylmethylamine (TOMA) coated silica wafers was used and imaging was carried out by topographic and lateral atomic force microscopy (AFM) scanning as described (Koo et al. 2010 (link); Galanakis et al. 2021 (link)). For enhanced image resolution, a modified graphite (MG) surface (water droplet angle 45.5° ± 0.5°, n = 3) was used as described (Protopopova et al. 2014 ) Briefly, a 2-μl aliquot of fg 5 μg/ml solution was applied for 5–15 s, immediately diluted with 100 μl deionized water for 10 s, dried by forced air, and scanned by AFM in tapping mode using super-sharpened cantilevers, SSS-SEIHR (Nanosensors, Germany) with a tip radius < 0.5 nm, and the MFP-3D AFM microscope (Asylum Research, Oxford Instruments, USA).

The nanostructure of vector/siRNA complexes was imaged on atomic force microscopy (AFM). Briefly, AFM images were obtained on MFP-3D AFM microscope (Oxford Instruments Asylum Research, Inc., Santa Barbara, CA) under acoustic AC mode using Si probes operating at a resonant frequency of 154 kHz. All measurements were carried out at room temperature and acquired images had a resolution of 512 × 512 pixels collected at a speed of one line min⁻¹. Freshly cleaved mica surface was used as the substrate for imaging. To acquire images, about 50 µl of the prepared sample was pipetted on to the mice surface and allowed to interact with the surface for 5 min. Mica was then washed with RNase-free water to remove unattached complexes. After air-drying, the mica surface was analyzed by MFP-3D AFM at room temperature using the tapping mode. Post image processing of AFM images was done using the IGOR Pro 6.37 software (WaveMetrics, Lake Oswego, OR).