Fig. 1.

Nanoparticle tracking analysis and Western blotting confirm purity of SARS-CoV2 preparations, whereas targeted lipidomics demonstrates the membrane as a PL-rich membrane mainly comprised of PE, PC, and PI. A and B: purity analysis of gradient purified viral preparations. A: Gradient purified virus was analyzed by nanoparticle tracking analysis and particle size plotted. B: Proteins were solubilized in NuPAGE LDS buffer and then separated by size on Bis-Tris gels, before being transferred to nitrocellulose and blotted for the indicated proteins, as outlined in Materials and methods section (see supplemental Fig. S1 for uncropped gels). C: Lipidomics analysis of the total amounts of lipids in each category in Vero and A549 cells. Lipids were extracted from three preparations of virus from either Vero or A549 cells and analyzed using LC/MS/MS, as indicated in the Materials and methods section. The relative percent of all detected lipid categories for all three preparations, with molecular species within each category combined to provide total values, is shown. Amounts (nanogram) of all individual molecular species were added together for each preparation and then converted to molar amounts using an average mass value per category. Molar% was then calculated following totaling of all lipid categories (n = 3, mean ± SEM). Unpaired Student's t-test.