Fcf200h cu tb

Morphology and size
distribution were investigated for the three production batches of
MMIR1 and MMIR– by drop casting (20 μg/mL, 2 μL)
and dried overnight on Formvar/Carbon-coated hexagonal copper mesh
grids (FCF200H-CU-TB, Electron Microscopy Sciences). The grids were
observed on a JEM 1010 TEM (Jeol, Ltd., Japan) equipped with a charge-coupled
device side-mounted Veleta camera (Emsis, Germany). NP size was measured
manually using ImageJ software (NIH, USA).

Seven microliters of pelleted plasma resuspended in complete medium or plasma-derived viral progeny produced on Vero E6 cells was spotted onto copper hexagonal EM grids (#FCF200H-Cu-TB, Electron Microscopy Sciences, Hatfield, PA, USA). Complete medium only or plasma of a COVID-19-negative patient and a virus stock of porcine respiratory coronavirus (strain 20v17) functioned as negative and positive controls, respectively (Fig. S4c). Grids were washed one time in ultrapure water prior to negative staining with 1% uranyl acetate for 45 s. EM grids were observed using a JEOL JEM-1400 Plus transmission electron microscope and Radius v1.4 software.