Autofluorescence properties of colonic mucosa: dependence on excitation wavelength

The dependence of autofluorescence properties on the excitation wavelength was studied on colon tissue, comparing neoplastic with non-neoplastic tissues. Studies were performed both on tissue sections and on whole tissue from biopsies of surgical resection, using microscopic and optic fiber devices, respectively. The excitation wavelengths 366, 405 and 436 nm, corresponding to emission lines of Mercury lamp, were considered. The results indicate that the emission intensity and spectral shape of autofluorescence of both the histological components of tissue and of the whole tissue are affected by the excitation wavelength to an extent varying with tissue condition. Excitation at 366 nm enhances the differences between non-neoplastic and neoplastic tissues in the spectral region mainly related to the tissue metabolism (NADH); excitation at 436 nm favors the differences attributable to the tissue alteration arising from tumor host-response. The findings provide useful information for optimizing autofluorescence-based technique in tumor diagnosis.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.