document: resuspended in PBS buffer, followed by 20% w/v PEG8000-NaCl precipitation to obtain pure VLPs. VLPs were resuspended in 1 mL PBS buffer and extracted with 1:1 n-butanol:chloroform. The VLP-based samples from the aqueous layer were purified by step sucrose gradient ultracentrifugation and then precipitated with 20% w/v PEG8000/2 M NaCl solution and resuspended in 25 mL of PBS buffer, followed by exhaustive dialysis (SnakeSkin® Dialysis Tubing, 10,000 MWCO. Thermo, LOT: QD213952, USA) against PBS