A single-atom-thick mesh of carbon can protect living animal cells from being damaged under an electron microscope, and could lead to better cell images.

Tissue samples are typically dried and chemically treated to protect them from the vacuum of electron microscopes, but this kills cells and can introduce structural artefacts. As an alternative, Ke Xu of the University of California, Berkeley, and his colleagues used graphene — which is conductive but impermeable to gas and liquid — to insulate live, untreated mammalian cells against the microscope's harsh environment. The team obtained images that correlated well with other live-cell imaging methods.

In another study, David Weitz of Harvard University in Cambridge, Massachusetts, and his team used 3–10 layers of graphene sheets to encapsulate liquid samples for transmission electron microscopy. They imaged influenza viruses and cells in their native state.

Nature Commun. 6, 7384 (2015); NanoLett.http://doi.org/5gp(2015)