AFM images were recorded in air by using a Nanoscope V Multimode 8 (Bruker, Santa Barbara, CA, USA) in PeakForce Tapping (PFT) mode using Scanasyst-Air probes (Bruker). Continuous force–distance curves were thus recorded with an amplitude of 100–300 nm at low frequency (1–2 kHz). PFT mode decreases the lateral and shear forces. Images were recorded at 2048 × 2048 pixels at a line rate of 1.5 Hz. Images shown in the figures are representative of three different and independent samples. The ‘particle analysis’ tool in the Nanoscope Analysis software (version 1.50) was used to determine the heights of the adsorbed mRNPs from at least three independent samples. Basically, for each particle of interest, the particle analysis tool measured the maximum height of the particle. The length of nucleoprotein filaments was measured by using the ImageJ software manually.
Indicated amounts of proteins and nucleic acids were incubated in 20 μl of binding buffer (10 mM Hepes, pH 7.5, 30 mM KCl, 1 mM Putrescine) for 5 min at room temperature. Putrescine, a natural polyamine, was added to the buffer to adsorb mRNPs on mica (36 (link)). Then, samples were deposited on the mica surface and dried. The method is described in details in ref. (36 (link)).
Indicated amounts of proteins and nucleic acids were incubated in 20 μl of binding buffer (10 mM Hepes, pH 7.5, 30 mM KCl, 1 mM Putrescine) for 5 min at room temperature. Putrescine, a natural polyamine, was added to the buffer to adsorb mRNPs on mica (36 (link)). Then, samples were deposited on the mica surface and dried. The method is described in details in ref. (36 (link)).
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