Combining IR spectroscopy with fluorescence imaging in a single microscope: Biomedical applications using a synchrotron infrared source (invited)

Abstract

It has become increasingly clear that infrared microspectroscopy (IRMS) can be an extremely valuable analysis tool when determining the chemical composition of biological and biomedical samples. Frequently, fluorescence illumination is required for sample characterization, and is usually achieved on a separate and dedicated optical microscope. We report the development and use of a single microscope for concomitant fluorescence and synchrotron IRMS. This unique combination has been used to identify changes in the composition of newly remodeled bone after the onset of osteoporosis, misfolded protein structure in Alzheimer’s disease, and cellular changes in apoptosis.

Organic matter stabilization in soil microaggregates: implications from spatial heterogeneity of organic carbon contents and carbon forms

“…Here we applied synchrotron-based microspectroscopy, using x-ray focusing optics (Jacobsen et al 2000) coupled with C K-edge signal acquisition (NEXAFS) and Fourier-transform infrared (FTIR) spectroscopy (Miller et al 2002), to map C contents and forms at a spatial resolution of 0.05-5 m. The FTIR mapping also shows the location of organic C forms in relation to mineral surfaces, thus providing direct evidence for the relative importance of the two modes of microaggregate formation. Using an improved soil sectioning technique, we were able to investigate entire microaggregates for the Wrst time, signiWcantly expanding our earlier NEXAFS experiments ) and enabling use of FTIR in transmission mode at high spatial resolution.…”

Synchrotron Radiation Spectroscopic Techniques as Tools for the Medicinal Chemist: Microprobe X-Ray Fluorescence Imaging, X-Ray Absorption Spectroscopy, and Infrared Microspectroscopy

“…Finally, the use of SR-FTIR microspectroscopy for studying the biomolecular effects of drugs in vivo and in cell culture has become prominent in the last 5 years with studies of anticancer drugs, [92,[108][109]125] osteoporosis drugs, [102] and photodynamic therapeutics [111][112] showing distinguishable biomolecular changes. Issues associated with Mie scatter distortion of the spectra are being addressed, [92,[122][123][124] and the technique is being critically assessed with a goal to using it for preclinical and clinical evaluation of drug candidates.…”

“…[102] The most sophisticated of the experiments was the study of the effect of the drug, nandrolone decanoate (an anabolic steroid that enhances bone density in osteoporotic women) in female monkeys that had undergone ovariectomies to induce osteoporosis. [102,129] The monkeys were administered different fluorochrome labels at 1 (calcein) and 2 years (alizarin) after the ovariectomy, to identify the new bone using fluorescence microscope. The areas were analysed by SR-FTIR microspectroscopy and the phosphate/protein ratio was studied with reference to control monkeys.…”

“…[102] For the first time, an IR microscope had been modified to allow simultaneous fluorescence sample visualisation and IR analysis. [102] The capabilities were exploited for experiments ranging from studies of osteoporosis, to…”

“…[92] There have since been significant developments towards disease diagnosis, improvements in the understanding of disease progression and validations of hypotheses regarding diseases such as prostate, [93] skin, [94] colon, [95] cervical, [94,96] and breast cancers, [97] melanoma, [98] leukemia, [99] transmissible spongiform encephalopathies/prion diseases, [100] Alzheimers disease, [101][102] diabetes, [103] malaria, [104] ophthalmic disorders, [105] and arthritic disorders. [94,99] The usefulness of SR-FTIR microspectroscopy derives from the fact that the IR source is 10-1000 times more brilliant than the conventional globar source.…”