Features | Partner Sites | Information | LinkXpress
Sign In
GLOBETECH PUBLISHING LLC
GLOBETECH PUBLISHING LLC
GLOBETECH MEDIA

Researchers Employ High-Energy X-Ray to Image Living Cancer Cells

By BiotechDaily International staff writers
Posted on 13 Mar 2014
Image: X-ray scan of biologic cells: Each pixel represents a complete diffraction image. The color indicates how strong the X-rays are scattered at this local point (Photo courtesy of Britta Weinhausen, the University of Göttingen).
Image: X-ray scan of biologic cells: Each pixel represents a complete diffraction image. The color indicates how strong the X-rays are scattered at this local point (Photo courtesy of Britta Weinhausen, the University of Göttingen).
Scientists have performed the first studies of living biologic cells using high-energy X-rays. In the future, the new technique should make it possible to study unaltered living cells at high resolution.

“The new method for the first time enables us to investigate the internal structures of living cells in their natural environment using hard X-rays,” reported the researchers from the working group. “Thanks to the ever-greater resolution of the various investigative techniques, it is increasingly important to know whether the internal structure of the sample changes during sample preparation.” Scientists are working on the new research at the Deutsches Elektronen-Synchrotron DESY (Hamburg, Germany) PETRA III research light source. The new technology reveals distinct differences in the internal cellular structure between the living and dead, chemically fixed cells. “The new method for the first time enables us to investigate the internal structures of living cells in their natural environment using hard X-rays,” emphasized the leader of the working group, Prof. Sarah Köster from the Institute for X-Ray Physics of the University of Göttingen (Germany). The researchers published their findings on February 25, 2014, in the scientific journal Physical Review Letters.

Due to newly developed analytic methods with ever-higher resolution, scientists now can study biologic cells at the level of individual molecules. The cells are frequently chemically fixed before they are studied with the help of optical X-ray or electron microscopes. The process of chemical fixation involves immersing the cells in a type of chemical preservative that fixes all of the cell’s organelles and even the proteins in place. “Minor changes to the internal structure of the cells are unavoidable in this process,” stated Prof. Köster. “In our studies, we were able to show these changes in direct comparison for the first time.”

The scientists used cancer cells from the adrenal cortex for their study. They grew the cells on a silicon nitrite substrate, which is nearly transparent to X-rays. To keep the cells alive in the experimental chamber during the research, they were supplied with nutrients, and their metabolic products were driven away via fine channels only 0.5 mm in diameter. “The biological cells are thus located in a sample environment which very closely resembles their natural environment,” explained Dr. Britta Weinhausen from Prof. Köster’s group, the article’s first author.

The research was performed at the Nanofocus Setup (GINIX) of PETRA III’s experimental station P10. The scientists used the brilliant X-ray beam from PETRA III to scan the cells to gather data about their internal nanostructure. “Each frame was exposed for just 0.05 seconds, in order to avoid damaging the living cells too quickly,” clarified coauthor Dr. Michael Sprung from DESY. “Even nanometer-scale structures can be measured with the GINIX assembly, thanks to the combination of PETRA III’s high brilliance and the GINIX setup which is matched to the source.”

The researchers studied living and chemically fixed cells using this so-called nanodiffraction technique and compared the cells’ internal structures on the basis of the X-ray diffraction images. The results showed that the chemical fixation produces noticeable differences in the cellular structure on a scale of 30–50 nm.

“Thanks to the ever-greater resolution of the various investigative techniques, it is increasingly important to know whether the internal structure of the sample changes during sample preparation,” clarified Prof. Köster.

In the future, this new technology will make it possible to examine unchanged living cells at high resolution. Although other techniques have an even higher resolution than X-ray scattering, they require a chemical fixation or complex and invasive preparation of the cells. Lower-energy, so-called soft X-rays have already been used for studies of living cells. However, the study of structures with sizes as small as 12 nm first becomes possible through the analysis of diffraction images generated using hard X-rays.

Related Links:

Deutsches Elektronen-Synchrotron DESY
Institute for X-Ray Physics of the University of Göttingen



Channels

Genomics/Proteomics

view channel
Image: The photo shows a mouse pancreatic islet as seen by light microscopy. Beta cells can be recognized by the green insulin staining. Glucagon is labeled in red and the nuclei in blue (Photo courtesy of Wikimedia Commons).

Regenerative Potential Is a Trait of Mature Tissues, Not an Innate Feature of Newly Born Cells

Diabetes researchers have found that the ability of insulin-producing beta cells to replicate and respond to elevated glucose concentrations is absent in very young animals and does not appear until after weaning.... Read more

Drug Discovery

view channel
Image: Wafers like the one shown here are used to create “organ-on-a-chip” devices to model human tissue (Photo courtesy of Dr. Anurag Mathur, University of California, Berkeley).

Human Heart-on-a-Chip Cultures May Replace Animal Models for Drug Development and Safety Screening

Human heart cells growing in an easily monitored silicon chip culture system may one day replace animal-based model systems for drug development and safety screening. Drug discovery and development... Read more

Biochemistry

view channel
Image:  Model depiction of a novel cellular mechanism by which regulation of cryptochromes Cry1 and Cry2 enables coordination of a protective transcriptional response to DNA damage caused by genotoxic stress (Photo courtesy of the journal eLife, March 2015, Papp SJ, Huber AL, et al.).

Two Proteins Critical for Circadian Cycles Protect Cells from Mutations

Scientists have discovered that two proteins critical for maintaining healthy day-night cycles also have an unexpected role in DNA repair and protecting cells against genetic mutations that could lead... Read more

Business

view channel

Roche Acquires Signature Diagnostics to Advance Translational Research

Roche (Basel, Switzerland) will advance translational research for next generation sequencing (NGS) diagnostics by leveraging the unique expertise of Signature Diagnostics AG (Potsdam, Germany) in biobanks and development of novel NGS diagnostic assays. Signature Diagnostics is a privately held translational oncology... Read more
 
Copyright © 2000-2015 Globetech Media. All rights reserved.