SYNCHROTRON-POWERED FT-IR MICROSPECTROSCOPY - SINGLE-CELL INTERROGATION

Excellent spatial resolution is achieved with an integrated FT-IR micr ospectrometer (IR mu s, Spectra-Tech) in which the globar (thermal) so urce is replaced by synchrotron radiation. The infrared portion of the spectrum extracted From the vacuum ultraviolet storage ring of the Na tional Synchrotron Light Source (NSLS) of the Brookhaven National Labo ratory, is not only brighter, but is free from thermal noise and conce ntrated into a small area. Passing the beam with low divergence throug h an aperture does not severely attenuate the throughput as is the cas e with a thermal source. Spectra obtained with 5 and 6 mu m diameter a pertures from adjacent tissue in a mouse retina, a wheat aleurone cell and cell wall, and two cells in wheat primary root, have shown locali zed 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.