Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Researchers demonstrate nanoscale X-ray imaging of bacterial cells

Sharper vision for new insights into biological questions, including DNA repair

An ultra-high-resolution imaging technique using X-ray diffraction is a step closer to fulfilling its promise as a window on nanometer-scale structures in biological samples.

In the Proceedings of the National Academy of Sciences, researchers report progress in applying an approach to "lensless" X-ray microscopy that they introduced one year ago. They have produced the first images, using this technique, of biological cells – specifically the intriguing polyextremophile Deinococcus radiourans.

Better ability to see nanoscale structures in cells could yield important insights for evolutionary biology and biotechnology. In the case of D. radiourans, for example, it could help to settle questions about whether – or how – the structure of this organism's DNA-bearing nucleoid region accounts for its hardiness against ionizing radiation. Having demonstrated the resolution, reliability, and reproducibility of their technique, the researchers are now working to extend it to three-dimensional imaging of biological cells.

X-ray imaging is best known for its medical applications, such as traditional radiographs and CT scans. Yet the use of X-rays goes far beyond routine imaging. In particular, the very short wavelength of X-ray radiation allows various modes of microscopy that can reach the nanometer resolution. One of the main hurdles to high-resolution X-ray microscopy is the difficulty of producing high-quality X-ray lenses. To overcome these difficulties, so-called "lensless" microscopy methods have emerged in the last decade. A technique developed by researchers now in the biomedical physics group at Technische Universitaet Muenchen (TUM) has shown great promise for ultra-high resolution imaging of materials and life science samples.

This imaging technique, called ptychography, was first introduced in the 1970s for electron diffraction. It consists in measuring full far-field diffraction patterns as a small illumination is scanned on a sample. While its use in electron microscopy is still limited, ptychography has gained tremendous popularity in the X-ray imaging community in the last few years, thanks to the development by Franz Pfeiffer, now chair of the biomedical physics group at TUM, and his team. A critical step in the development of ptychography was published by the team one year ago in Science. The super-resolution capability of the imaging method was successfully demonstrated with a gold test structure.

Now a collaboration of the Pfeiffer group, together with researchers at University of Goettingen and at the Swiss Light Source (Villigen, Switzerland), has gone a step further and produced the first images of biological cells with the same technique.

These results, published in the Proceedings of the National Academy of Sciences, show that lensless X-ray imaging, in particular ptychography, can be used to obtain accurate maps of the electron density forming a biological sample. This type of quantitative measurement is extremely difficult with most other high-resolution techniques currently available. Moreover, biological samples are very fragile and nearly transparent to X-rays, making this type of accurate measurement even more challenging.

The Pfeiffer group is now moving beyond this success and looking into ways of improving the technique further. In particular, the team is aiming at the next milestone: three-dimensional imaging of biological samples.

This research is supported by the German Research Foundation (DFG), the Helmholtz Society, and the German Ministry of Education and Research.


K. Giewekemeyer, P. Thibault, S. Kalbfleisch, A. Beerlink, C. M. Kewish, M. Dierolf, F. Pfeiffer, T. Salditt, Quantitative biological imaging by ptychographic x-ray diffraction microscopy, PNAS Early Edition, Proceedings of the National Academy of Sciences of the USA, Dec. 7-11, 2009.

P. Thibault, M. Dierolf, A. Menzel, O. Bunk, C. David, F. Pfeiffer, High-resolution scanning x-ray diffraction microscopy, Science 321, 379 – 381 (2008).

Prof. Dr. Franz Pfeiffer
Chair for biomedical physics (E17)
Physics Department TUM
phone: +49 89 289 12552
Dr. Pierre Thibault
Physics Department TUM
phone: +49 89 289 14397
Technische Universitaet Muenchen (TUM) is one of Germany's leading universities. It has roughly 440 professors, 6,500 academic and non-academic staff (including those at the university hospital "Rechts der Isar"), and 24,000 students. It focuses on the engineering sciences, natural sciences, life sciences, medicine, and economic sciences. After winning numerous awards, it was selected as an "Elite University" in 2006 by the Science Council (Wissenschaftsrat) and the German Research Foundation (DFG). The university's global network includes an outpost in Singapore. TUM is dedicated to the ideal of a top-level research based entrepreneurial university.

Andreas Battenberg | EurekAlert!
Further information:

More articles from Physics and Astronomy:

nachricht Physicists made crystal lattice from polaritons
20.03.2018 | ITMO University

nachricht Mars' oceans formed early, possibly aided by massive volcanic eruptions
20.03.2018 | University of California - Berkeley

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

Physicists made crystal lattice from polaritons

20.03.2018 | Physics and Astronomy

Mars' oceans formed early, possibly aided by massive volcanic eruptions

20.03.2018 | Physics and Astronomy

Thawing permafrost produces more methane than expected

20.03.2018 | Earth Sciences

Science & Research
Overview of more VideoLinks >>>