Helium Ion Microscope

New images of the SARS-CoV-2 coronavirus demonstrate the potential of the helium ion microscopy in bioimaging, especially for the imaging of interactions between viruses and their host organisms.

This helium ion microscope image shows SARS-CoV-2 virus particles (blue). Image credit: N. Frese / Bielefeld University.

Helium ion microscopy offers the opportunity to obtain direct views of biological samples such as cellular structures, virus particles, and microbial interactions.

Imaging with this technique combines sub-nanometer resolution, large depth of field, and high surface sensitivity.

Due to its charge compensation capability, the helium ion microscopy can image insulating biological samples without additional conductive coatings.

“This conductive coating changes the surface structure of the sample,” said Professor Armin Gölzhäuser, a researcher in the Faculty of Physics at Bielefeld University.

“Helium ion microscopy does not require a coating and therefore allows direct scanning.”

“Our 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,” added Dr. Natalie Frese, also from the Faculty of Physics at Bielefeld University.

Using the helium ion microscope, the researchers captured images of Vero E6 cells infected with SARS-CoV-2.

Their images unveil the 3D appearance of the virus and the surface of Vero E6 cells with an edge resolution of up to 1.3 nm.

“Helium ion microscopy is well suited for imaging the cell’s defense mechanisms that take place at the cell membrane,” said Professor Friedemann Weber, a virologist in the Institute of Virology at the Justus-Liebig-University Giessen.

“This method is a significant improvement for imaging the SARS-CoV-2 virus interacting with the infected cell,” said Professor Holger Sudhoff, head physician at the University Clinic for Otolaryngology, Head and Neck Surgery at Bielefeld University.

“Helium ion microscopy can help to better understand the infection process in COVID-19 sufferers.”

The team’s paper was published in the Beilstein Journal of Nanotechnology.

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Natalie Frese et al. 2021. Imaging of SARS-CoV-2 infected Vero E6 cells by helium ion microscopy. Beilstein J. Nanotechnol 12: 172-179; doi: 10.3762/bjnano.12.13