Fig. 2
TEM analysis of VLP assembly of non-tagged and His-tagged TEV CP versions. a The samples were adsorbed on Formvar-coated copper grids and negatively stained with 2% uranyl acetate aqueous solution. The grids were examined using TEM JEM-100C (JEOL, Japan) at an accelerating voltage of 80 kV. TEV-CP lysate: TSP of TEV-CP preparation at 100,000x magnification; His-TEV-CP lysate: TSP of His-TEV-CP preparation at 100,000x magnification; TEV-CP purified: soluble fraction recovered from precipitation of TEV-CP extract using PEG 8000 3% and 500 mM NaCl at 50,000x magnification; His-TEV-CP purified: Ni2+ affinity purified His-TEV-CP (0.4 mg/ml) in MB, 500 mM NaCl at 50,000x magnification. b Visualization of nucleic acid content in purified His-TEV-CP VLPs sample analyzed in agarose gels. A sample of 25 μl of purified particle solution (0.2 mg/ml) was loaded in 0.8 agarose gel in Tris, acetic cid, EDTA (TAE) buffer. The particles were treated with Laemmli sample buffer (2x) for 10 min at 95 °C. Nucleic acids in gel were visualized using SYBR Safe DNA gel stain (Thermo Fisher Scientific, USA) included in the sample with Gel Doc EZ System (BioRad, USA) using a blue light tray. Proteins were identified with 0.1% Coomassie G-250 dye in 10% ethanol and 10% acetic acid and destained in the same solution without Coomassie dye