Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Brilliant light source for X-ray microscopy permits three-dimensional imaging of biological cells

12.12.2008
The Fraunhofer Institute for Laser Technology ILT in Aachen has developed a powerful light source for compact X-ray microscopes that will allow biological cells to be studied in high resolution. Using a technique similar to that of medical tomography, it is now possible to obtain layered three-dimensional images of biological cells or even semiconductor devices.

The task of analyzing the internal structure of biological cells is a relatively complex affair. When using an electron microscope, the whole cells first have to be fixed, followed by the time-consuming task of preparing the individual slices. The surface of the slices can then be analyzed at high resolution, one slice at a time.


Image of a diatom (silica algae) taken using the X-ray microscope developed by the Fraunhofer Institute for Laser Technology ILT, Aachen, Germany

The procedure is much less laborious when using an X-ray microscope. Immediately after cryo-fixing of the whole cells, it is possible to obtain 3-dimensional images with a resolution of 20 nanometers (at current standards). The technique is rather similar to that of medical tomography (CAT scanning). X-ray microscopes can also be used in semiconductor electronics to examine current-carrying circuits at high resolution. This allows defects to be detected and visualized in working electronic devices.

To achieve the comparatively high resolution of 20 nanometers that distinguishes X-ray microscopy from basic light microscopy, a short-wavelength source in the soft X-ray range is required. Furthermore, the appropriate short exposure times call for the presence of a high photon flux. To date, the usual way of generating the necessary photon flow has involved the use of an electron storage ring. Such facilities are only available in a limited number of major research centers, and can only be used on-site, which makes it difficult for many users to take advantage of them.

The Fraunhofer Institute for Laser Technology has now developed a compact, integrated light source/collector lens system that enables powerful X-ray microscopes to be built on a laboratory scale. The volume of the resulting X-ray microscope does not exceed 2 m3. This permits it to be installed wherever it is needed.

The new X-ray microscope is capable of operating with exposure times in the single-digit second range for thin samples of less than 1 micrometer, or several tens of seconds for larger biological samples with a thickness of a few micrometers. Dr. Klaus Bergmann, who leads the Fraunhofer ILT project team, is certain that, "we will be able to bring the exposure time down to below 10 seconds for the larger samples too, by optimizing the design of the condenser mirror."

A hollow-cathode-triggered pinch plasma is employed as the light source. The nitrogen working gas is repeatedly ionized in a pulsed high-current discharge, and briefly heated to a temperature of several hundred thousand degrees Celsius. Part of the coupled energy is emitted in the form of characteristic X-rays at a wavelength of 2.88 nanometers. The source can produce 4 x 10exp13 photons/(sr x pulse) at the 1s2-1s2p transitions of helium-like nitrogen. Using a suitably adapted collector optic and a pulse repetition rate of 1000 Hz, a photon flux of 1 x 10exp7 photons/(µmexp2 x s) can be generated on the sample. At this density, microscopic images of thick aqueous samples can be obtained with an exposure time of approximately ten seconds.

A first demonstrator model of the microscope has been built in collaboration with the Institute for X-Ray-Optics at the University of Applied Sciences in Koblenz and the company ACCEL Instruments GmbH in Bergisch-Gladbach, as part of a BMBF-funded collaborative research project. Next year's objective is to produce a light source for a commercial X-ray microscope suitable for tomography applications by integrating an appropriately adapted collector optic and further improving the brilliance.

CONTACTS at the Fraunhofer ILT:

If you have any questions about the X-ray microscope, please contact our experts:
Dr. rer. nat. Klaus Bergmann
Plasma technology department
Fraunhofer Institute for Laser Technology ILT
Phone +49 (0)241/8906-302
Fax +49 (0)241/8906-121
klaus.bergmann@ilt.fraunhofer.de
Dr. Willi Neff
Head of the plasma technology department
Fraunhofer Institute for Laser Technology ILT
Phone +49 (0)241/8906-142
Fax +49 (0)241/8906-121
willi.neff@ilt.fraunhofer.de
If you have questions concerning other subjects and wish to be put in touch with the relevant expert, please contact:
Dipl.-Phys. Axel Bauer
Head of Marketing and Communications
Fraunhofer Institute for Laser Technology ILT
Phone +49 (0)241/8906-194
Fax +49 (0)241/8906-121
axel.bauer@ilt.fraunhofer.de

Axel Bauer | Fraunhofer Gesellschaft
Further information:
http://www.ilt.fraunhofer.de/eng/100031.html

More articles from Physics and Astronomy:

nachricht NASA detects solar flare pulses at Sun and Earth
17.11.2017 | NASA/Goddard Space Flight Center

nachricht Pluto's hydrocarbon haze keeps dwarf planet colder than expected
16.11.2017 | University of California - Santa Cruz

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: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>