Transmission Electron Microscopy
Observation of viruses and VLPs by TEM is done on thin sections of pelleted samples embedded in resin or negative staining of a certain number of cell profiles.
For the investigation of cell substrates used in the manufacture of biopharmaceuticals to test for the presence of virus-like particles, the Federal Drug Administration (FDA), Center for Biologics Evaluation and Research (CBER), and the European Medicines Agency (EMA) guidelines recommend the use of TEM.
TEM is the only method to show the morphology and structure of the virus.