Late stage FHV infected DL1 cells prepared by conventional aldehyde fixation and embedding methods (CAF) (A, D, G, J), fixed and HPF (CAF-HPF) (B, E, H, K) and HPF alone (C, F, I, L) were examined by thin section EM. A higher magnification view of the aggregates of FHV in each DL1 cell in A (3x), B (3.5x) and C (3.5x) are shown in D, E and F respectively. The diameter of an individual FHV is 30 nm. A plot of the positions of the viruses centers in the boxed areas in D, E, and F are displayed in G, H and I, respectively and illustrating a more crystalline arrangement in H and I as compared with G. (J–L) Morphology of an appropriated mitochondrion in each preparation method. An arrow in each micrograph points to a spherule. Note how similar the mitochondrial morphologies are in the insets in K and L as compared to that in J, which appears empty and swollen.