FIGURE 8.3 Negative Staining Transmission Electron Microscopy (NSTEM) observation of viral preparations. A − Sucrose cushion and sucrose

gradient purified preparation of influenza virus, extracellular vesicles or influenza virus like particles. B – Immunogold labeling of sucrose cushion and

sucrose gradient purified preparation of influenza virus. C – Several purification steps of culture supernatant.

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Bioprocessing of Viral Vaccines