Polyester film as an advantageous tool for light and ultrastructural examination of single cells infected with viruses.

The use of marked transparent polyester film as a support of cell monolayer, smears or sections (cryostat or paraffin), makes possible to examine the same cell preselected in the light microscope by electron microscope (EM). Consequently, this technique enables to use histological or immunohistological investigations (using immunofluorescence or peroxidase (Px) labelling) by light microscopy before examination in EM. As example we used herpes simplex virus (HSV) type 1-infected cells grown on the above mentioned polyester film. Visualization of the antigen with hyperimmune serum and Px-labelled antiserum was followed by examination of selected cells in EM, where viral particles were clearly visible.