Sd r150 t3l450b 10

The atomic force microscope (AFM) NTEGRA Prima (NT-MDT, Russian Federation) was used to obtain сell and membrane images and to measure local stiffness of RBC membranes in a liquid. To acquire images, NSG01 cantilevers (Nanosensors, Switzerland) with a force constant of 5 N/m and tip radius of 10 nm were used. The numbers of scan points were 512 and 1024. Measurements of local stiffness of RBC membranes were performed by ASF on the vertical displacement of a piezoscanner, where the sample was placed [14 (link), 23 (link)]. To measure the deformation of the membrane, the type SD-R150-T3L450B-10 (Nanosensors, Switzerland) cantilever was used. The radius of the cantilever probe was 150 nm, the coefficient of elasticity was 1 N/m, the probe height was 15 μm, and the resonance frequency was 21 kHz.
To measure stiffness, RBCs were scanned in an AFM field 100 × 100 μm²; a group of cells was selected for the study and scanned in the field of 30 × 30 μm². Then, in the atomic force spectroscopy mode, a marker was placed on the cell image and the region was exposed to an indenter (probe) with the force F. The characteristics and peculiarities of deep penetrations of the probe into the membrane were studied. That is, curves of the piezoscanner's approach was used in the analysis of the experimental data, I(z) and correspondingly F(h).

The stiffness of pRBC membranes is characterized by Young's modulus (E). The method of sedimentation was used to prepare the sample. To do this, 300 μl of pRBC suspension (SFe²⁺1700 and SFe²⁺0) was applied to glass coverslips coated in poly-L-lysine hydrobromide (MP Biomedicals, France) and was left for 30 minutes for adhesion. Then, the coverslips were washed in PBS. For this, the type of cantilever SD-R150-T3L450B-10 (Nanosensors, Switzerland) was used (probe radius 150 nm, resonance frequency 21 kHz, force constant 1 N/m). Force curves were measured only on native cells, without adding chemical fixatives. Measurements were carried out after 1 and 24 hours.

The NTEGRA Prima atomic force microscope (NT-MDT Spectrum Instruments, Moscow, Russia) was used to capture images of cells and their cytoskeleton. The AFM 3D images were captured with NSG01 cantilevers that had a gold reflective surface, a 10 nm tip radius, and a spring constant range of 1.45–15.1 N/m (NT-MDT Spectrum Instruments, Russia). Scanning areas varied from 100 × 100 to 1 × 1 μm² in semi-contact operation mode. The resolution of each image spanned between 512 and 1024 points [29 (link),30 (link)]. Image processing was performed using FemtoScan Online software, Version 2.3.239 (5.2) (Advanced Technologies Center, Moscow, Russia, www.nanoscopy.ru (accessed on 12 January 2023)) [31 (link),32 (link),33 (link),34 (link)].
To assess the Young’s modulus of native cell membranes, the SD-R150-T3L450B-10 cantilever series (Nanosensors, Neuchatel, Switzerland) was selected, with a tip radius of 150 nm, a resonance frequency of ${\nu }^{\prime }=$ 21 kHz, and a stiffness coefficient of K = 1 N/m.
The cantilever series SD-R150-T3L450B-10 (Nanosensors, Switzerland) was used to measure the Young’s modulus of native cell membranes, with a probe radius of 150 nm, resonance frequency, and a stiffness coefficient of K = 1 N/m. All AFM images and force curves were made using SPM Nova software (NT-MDT Spectrum Instruments, Russia).