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December 2023 ESRFnews

BIO-IMAGING

M

ARCO di Michiel sees a lot of different

materials come to his beamline: battery

components, glasses, composites, sometimes

biominerals and cultural artefacts. What he very rarely

sees are soft biological samples. Composed of light

elements such as oxygen carbon and hydrogen these

are more or less invisible to the very highenergy Xray

beam that courses through the ID15A experimental

hutch Recently however di Michiel was asked to work

on a proposal by biologists at the University of Zurich

and ETH Zurich in Switzerland who were armed

with samples of human breast tumours tonsils and

appendixes As it turned out they really did need high

energy Xrays says di Michiel And in particular EBS

highenergy Xrays which have a very high flux

The reason was that the Zurich groups samples

were not purely biological Stained with various heavy

elements they were to be tests of a new biological imaging

technique, multi-element Z-tag X-ray fluorescence

(MEZ-XRF). The tests proved to be successful,

showing that MEZ-XRF could perform as well as other

leading comparable bio-imaging modalities, and with

the potential to perform much better. Non-destructive,

multiscale highspeed and able to identify at least

20 different tagged molecules at once it could help

scientists to understand in much greater detail which

types of tumours respond best to different types of

treatment There is even the possibility of making it 3D

We can look at up to 20 markers at the same time

across large tissue samples at high speed and in a non

destructive way even if the markers have low expression

says Merrick Strotton a first author on the study who is

now based at the UK research site of the multinational

biopharmaceutical company UCB Once weve looked

at the area in general and weve spotted the cells that

were interested in we can then zoom into specific

High-energy X-rays do not usually make much sense for

biological tissue samples, unless you are pioneering an entirely

new, EBS-enabled bio-imaging technique.

Bio-imaging, energised

Marco di Michiel helps researchers from Zurich test multi-element Z-tag X-ray fluorescence (MEZ-XRF).

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