IRENI multi-beam synchrotron slashes imaging time, reveals molecules

Milwaukee, WI--A new synchrotron-based imaging technique one million times brighter than sunlight captures high-resolution pictures of the molecular composition of tissues with unprecedented speed and quality. Carol Hirschmugl, a physicist at the University of Wisconsin-Milwaukee (UWM), led a team of researchers from UWM, the University of Illinois at Urbana-Champaign, and the University of Illinois at Chicago (UIC) to develop a new technique that uses multiple beams of synchrotron light to illuminate a state-of-the-art camera, instead of just one beam. Hirschmugl and UWM scientist Michael Nasse have built a facility, called Infrared Environmental Imaging (IRENI), to perform the technique at the Synchrotron Radiation Center (SRC) at UW-Madison.

IRENI cuts the amount of time needed to image a sample from hours to minutes, while quadrupling the range of the sample size and producing high-resolution images of samples that do not have to be tagged or stained as they would for imaging with an optical microscope. “Since IRENI reveals the molecular composition of a tissue sample, you can choose to look at the distribution of functional groups, such as proteins, carbohydrates and lipids,” says Hirschmugl, “so you concurrently get detailed structure and chemistry.”

Although not visible to the human eye, the mid-infrared range of light used by the team documents the light absorbed at thousands of locations on the sample, forming graphic “fingerprints” of biochemically important molecules. Using 12 beams of synchrotron light in this range allows researchers to collect thousands of these chemical fingerprints simultaneously, producing an image that is 100 times less pixelated than in conventional infrared imaging.

The work is a collaboration with the labs of Rohit Bhargava, assistant professor of bioengineering at the University of Illinois at Urbana-Champaign, and pathologists Dr. Virgilia Macias and Dr. André Kajdacsy-Balla at UIC. “It has taken three years to establish IRENI as a national user facility located at the SRC,” says Nasse. “It is the only facility of its kind worldwide.”

The team tested the technique on breast and prostate tissue samples to determine its capabilities for potential use in diagnostics for cancer and other diseases. The researchers were able to detect features that distinguished the epithelial cells, in which cancers begin, from the stromal cells, which are the type found in deeper tissues, with unprecedented detail. The new technique opens the door for development of synchrotron-based imaging that can monitor cellular processes, from simple metabolism to stem cell specialization.

SOURCE: University of Wisconsin-Milwaukee; www4.uwm.edu/news/stories/details.cfm?customel_datapageid_11602=3972285