Investigators from the National Synchrotron Light Source at the Brookhaven National Laboratory were able to marry two different imaging modalities–synchrotron-based infrared (FTIRM) and x-ray fluorescence (XRF) microscopies–to better understand organic composition and trace metal content of specimens. According to the researchers, their technique could aid in our understanding of processes behind such things as Alzheimer’s disease and the physiology of metal-reducing bacteria.
Synchrotron-based infrared (FTIRM) and x-ray fluorescence (XRF) microscopes are complementary tools for imaging the organic and trace metal composition of biological and environmental materials, respectively, without the need for extrinsic labels or stains. However, in order to directly correlate organic composition and trace metal content, it is important to precisely overlap the IR and XRF images. We have developed a gold-patterned sample substrate, where the grid pattern is sensitive to both x-ray and infrared light, and the resulting images can be used as fiducial markers for spatially overlapping the FTIRM and XRF images from the tissue. We show that FTIRM and XRF images can be correlated precisely. By combining FTIRM and XRF microprobe imaging on the same sample utilizing this sample substrate, a more complete picture of many disease states and exposure to environmental contaminants can be achieved by directly correlating the organic and trace metal ion distribution in the tissue…
In many biological and environmental systems, organic composition and trace metal content and distribution are often highly correlated. For example, plaques in Alzheimer’s diseased brain consist of both aggregates of the misfolded amyloid protein and the accumulation of metal ions such as copper and zinc. In the environment, metal-reducing bacteria and hyperaccumulating plants represent promising methods for remediation of contaminated soils…
The invention is essentially a micron-scale metallic marking grid upon which scientists place their samples – biological tissues or inorganic samples such as minerals – prior to imaging with different methods. “When the findings are analyzed, the grid can be used to ‘map,’ or orient, the images to one another, allowing us to study multiple variables in a single sample and better understand how they relate to one another,” said biophysicist Lisa Miller, leader of the team that developed the new method.
More about the technology: Microgrid Allows Simultaneous Study of Multiple Variables …
Technical introduction: A New Sample Substrate for Imaging and Correlating Organic and Trace-Metal Composition in Biological Cells and Tissues …
