Scientists capture first super-res X-rays of living cells

While lower-energy "soft" X-rays can already image living cells, the higher-energy "hard" ones that can view objects as small as a few nanometers haven't been able to -- until now.

Elizabeth Armstrong Moore
Elizabeth Armstrong Moore
Elizabeth Armstrong Moore is based in Portland, Oregon, and has written for Wired, The Christian Science Monitor, and public radio. Her semi-obscure hobbies include climbing, billiards, board games that take up a lot of space, and piano.
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To avoid damaging the cells, the researchers exposed them for only 0.05 seconds at a time, but still managed to image nanometer-scale structures. Britta Weinhausen/University of Göttingen

Typically, to view super small objects like molecules, the samples must first be dipped in a chemical preservative bath of death that keeps all parts entirely locked in place and thus viewable via very sophisticated tech such as X-ray devices and electron microscopes. The problem, of course, is that those molecules don't behave the same in death as they do in life, so while our current views of life at the nanoscale level are extremely detailed, they're technically speaking views of death, or at the very least, life frozen.

Now scientists at the University of Göttingen in Germany say that, using a new approach with one of the world's most sophisticated X-ray machines, the Petra III, they've been able to view -- however briefly -- actual living cells in their natural environment.

Reporting in the journal Physical Review Letters, the researchers say they grew cancer cells from the adrenal cortex on a silicon nitrate substance that is nearly transparent to X-rays. They then fed those cells nutrients and pumped away their metabolic products so that they could keep the cells alive in as close to a natural environment as possible while still being viewable by the higher-energy (aka "hard" X-ray) Petra III. While lower-energy "soft" X-rays can already image living cells, the resolution isn't as good.

To avoid killing the cells with the powerful X-ray beams, they exposed the sample in a series of frames that each lasted a mere 0.05 seconds. They then used this same nanodiffraction approach on chemically fixed cells for comparison and found that their cellular structures were noticeably different when viewed on a scale of 30 to 50 nanometers (that is, millionths of a millimeter).

While this initial test was performed using extremely brief and powerful blasts on petri dish cancer cells, the researchers say it offers evidence that we should be able to study living cells at super high resolution without first having to change their molecular behavior -- which could dramatically improve our understanding of life, including diseases and treatments, at the nanoscale level.