Synchrotron-Powered FT-IR Microspectroscopy: Single Cell Interrogation

Abstract

Excellent spatial resolution is achieved with an integrated FT-IR microspectrometer (IR mu s, Spectra-Tech) in which the globar (thermal) source is replaced by synchrotron radiation. The infrared portion of the spectrum extracted From the vacuum ultraviolet storage ring of the National Synchrotron Light Source (NSLS) of the Brookhaven National Laboratory, is not only brighter, but is free from thermal noise and concentrated into a small area. Passing the beam with low divergence through an aperture does not severely attenuate the throughput as is the case with a thermal source. Spectra obtained with 5 and 6 mu m diameter apertures from adjacent tissue in a mouse retina, a wheat aleurone cell and cell wall, and two cells in wheat primary root, have shown localized chemical differences. Functional group contour maps and 3D maps of mouse cerebellum, a grass vascular bundle and a cross-section of rye illustrate the utility of the system described