Quantifoil R2/1 Cu 300 TEM grids (Agar Scientific Ltd, Essex UK) were glow discharged prior to use to render them hydrophilic. LNP suspensions were automatically blotted with contact between the TEM grid surface and filter paper was pre-set to 3 or 6 s. They were then frozen in vitrified ice on these grids in liquid ethane using a Leica EM GP2 automatic plunge freezer and maintained under liquid nitrogen until required for analysis. A blotting time of 6s yielded satisfactory results for samples the 4mg/mL concentration samples presented in this paper.