Abstract
Ultraviolet resonance Raman (UVRR) spectroscopy was used to characterize normal and diseased colon mucosa in vitro. A tunable mode-locked Titanium:Sapphire laser operating at 76 MHz was used to irradiate normal and diseased colon tissue samples with 251 nm light generated from the third harmonic of the fundamental radiation. The Raman scattered light was collected and analyzed using a 1 meter spectrometer fitted with a UV coated, liquid nitrogen cooled CCD detector. The measured spectra show prominent bands that correspond to those of known tissue constituents including nucleic acids, aromatic amino acids and lipids. Using the Raman lineshapes measured from pure solutions of nucleotides, tryptophan, tyrosine, FAD, and from lipid-rich serosal fat, the colon spectra were modeled by a least square fitting algorithm whereby the colon spectra were assumed to be a linear combination of the pure biochemical lineshapes. The relative Raman scattering cross section of each biochemical was determined so that the relative concentration of each compound with respect to the others, could be extracted from a given tissue spectrum.