Scientists have succeeded for the first time in the SARS-CoV-2 imaging with a helium ion microscope. In contrast to the more conventional electron microscopy, the samples do not need a thin metal coating in helium ion microscopy. This allows interactions between the coronaviruses and their host cell to be observed particularly clearly. The study shows that the helium ion microscope is suitable for imaging coronaviruses – so precisely that the interaction between virus and host cell can be observed.
With scanning electron microscopy (SEM), an electron beam scans the cell and provides an image of the surface structure of the cell occupied by viruses. However, SEM has a disadvantage: the sample becomes electrostatically charged during the microscopy process and must be coated with an electrically conductive coating.
However, the conductive coating also changes the surface structure of the sample. Helium ion microscopy does not require a coating and therefore allows direct scanning. With the helium ion microscope, a beam of helium ions scans the surface of the sample for SARS-CoV-2 imaging. The helium ion microscope has a higher resolution and a greater depth of field.