SRC Quantum Lunch
Examining Tissue with Infrared Microspectroscopy: Challenges and Opportunities
While optical microscopy is an extremely useful tool for examining tissue samples, the intrinsic visible contrast between tissue types is low, necessitating the use of cumbersome sample staining techniques. Conversely, traditional absorption infrared spectroscopy gives chemical contrast by probing intrinsic molecular vibrations but lacks the imaging capabilities of microscopy. An amalgam of these two technologies was made practical with the declassification of infrared detector arrays approximately 15 years ago. Since then there has been significant progress in developing chemically-sensitive infrared microscopy - an imaging technology that uses intrinsic sample properties to distinguish tissue types. Our group at the University of Illinois at Urbana-Champaign (http://cisl.bioen.uiuc.edu/) is focused on making infrared microspectroscopic imaging a practical clinical tool for fast, reliable, automated and inexpensive tissue pathology.
The infrared intensity available from conventional sources is limited, resulting in restrictions on imaging capabilities. By using the high intensity infrared beamline at the SRC (and the attached high resolution infrared microscope), we are able to test and understand the limits of infrared microspectroscopic imaging. For example, the high resolution imaging allowed by the synchrotron source permits the diffraction-limited inspection of micron-scale tissue features. The high signal provided by the synchrotron also allows high-precision investigation of the light-matter interactions that affect data quality in infrared microscopy.